This guide is intended to compile the assist character information into one place for easy access. I am getting this out of the way right now. I'm not an expert on this game, nor on the information of this guide. I got most of the information from Mizuumi.wiki. So if you have questions, you'll have to either check there or look elsewhere. I didn't write [most of] this stuff, I'm just spreading it so more players will hopefully be able to use it to come up with more in-depth guides and then post them. That said, all the screenshots are mine, and anything like [this] is stuff I wrote. NOW... Without further adieu, let's get to it!

[This section is mine.]
Nitroplus Blasterz: Heroines Infinite Duel has a total of 20 characters to choose from as assists, and you choose 2 for every game mode.

Assist Characters take time to charge and recharge throughout a round.
The recharge meter is seperate from the power guages at the bottom.

You can call upon Assists 1 at a time, or both at the same time, but keep in mind that few if any assists take the exact same amount of time to recharge.

Some Assists can be summoned only on the ground while others can be called on the ground or in mid-air.

There are certain achievements earned through use of Assists:

Let's Dance Together - Use an Infinite Blast and 2 assists in 1 combo.
Over Here! - Use an assist 3 times.
Back Me Up - Cancel an attack and perform an Assist attack 3 times.
Partners Complete - Use all assists/partners.

Name: Aibara Natsumi
Debuted in: "Hello, world."
Voice Actor: Sakakibara Yui

The main heroine of "Hello, world." and a classmate of Kazuki, its protagonist. The story almost always comes back to her. The natural klutz but kind to everyone character, loves small animals and not good at thinking or at sports.

Assist Technique: The Brakes Don't Work for Some Reason
Startup - 9 seconds
Recovery - 30 seconds (on cancel) / 15 seconds (in neutral)

Natsumi rolls forward on her scooter, then comes back from the other side of the screen and tumbles. Deals multiple hits on its way, with the last few hitting low.

Name: Henri
Debuted in: Tenshi no Nichou Kenjuu -Angelos Armas-
Voice Actor: Saeki Ami

An angel with an appearance of a young girl and a strong-willed character. Hates people who die with regrets, calling them the "Sources of Dissonance".

Assist Technique: Bullet Storm
Startup - 9 seconds
Recovery - 30 seconds

Henri shoots a quick air-to-ground barrage of bullets in front of you.

Name: Franco il Nero
Debuted in: Zoku Satsuriku no Django -Jigoku no Shoukinkubi-
Voice Actor: Iwata Yuki

An outlaw hero from the planet of Sweetwater with a large bounty on her head. The great gun "Black Eagle" is her trademark. Has a carefree, easygoing personality.

Assist Technique: It's Showtime, Let's Kill'em!
Startup - 7 seconds
Recovery - 25 seconds

Franco throws a bottle and shoots with her gun. If the bottle hits the opponent, the shots are guaranteed to connect.

Name: Another Blood
Debuted in: Kishin Hishou Demonbane
Voice Actor: Kanda Rie

A mysterious girl in red who possesses the power of blood magic, she appears before Kurou and Al and reveals she is the blood edition of the Necronomicon.

Assist Technique: Violate, Forbidden Blood
Startup - 25 seconds
Recovery - 55 seconds (on cancel) / 25 seconds (in neutral)

A huge pillar comes from the ground. Huge damage and can OTG relaunch.

Name: Dragon
Debuted in: Dra†KoI
Voice Actor: Isshiki Hikaru

A mysterious girl with masculine speech patterns. She lacks common sense and tends to look down on everyone, but still remains a maiden who dreams of pure love.

Assist Technique: Dragon Breath
Startup - 20 seconds
Recovery - 40 seconds (on cancel) / 20 seconds (in neutral)

Dragon breathes a huge laser that covers the top half of the screen. Can be avoided by crouching down.

Name: Ishima Kaigen
Debuted in: Hanachirasu
Voice Actor: Hokuto Minami

A war weteran who has overthrown the Japanese government of the Showa era. After establishing the dictatorship of "Immortal Empire of Tokyo" and appointing herself as its prime minister, she has proceeded to protect its national spirit from the Western culture.

Assist Technique: Pledge of Cause - Hundred Million Honorable Deaths
Startup - 15 seconds
Recovery - 30 seconds

Kaigen rushes forward and cuts down the opponent, putting them into a crumple state.

Name: Spica
Debuted in: Sumaga
Voice Actor: Tezuka Maki

The self-proclaimed genius Etoile (witch). Since she was brought up in a noble family, she lacks common sense in some aspects of life, and although she doesn't bond with people too easily, she really cares for those who do matter to her.

Assist Technique: Star Strike
Startup - 7 seconds
Recovery - 25 seconds (on cancel) / 15 seconds (in neutral)

Spica shoots projectiles in a fanned pattern before her, then charges forward on her staff.

Name: Sakura
Debuted in: Axanael
Voice Actor: Aoyama Yukari

A blonde “gangster” who is strangely looking for Doujinshi on New Year’s Eve for her brother who is hospitalized. She is an honest, straightforward person who still has a girly side of being easily influenced by fortune-telling and the like.

Assist Technique: Bring it On
Startup - 7 seconds
Recovery - 15 seconds

[SHE NEEDS TO BE HIT BY AN ENEMY ATTACK TO USE HER COUNTERATTACK!]

Sakura appears before you with her back turned to the opponent. If she is hit with an enemy attack (physical or projectile, main character or partner), she charges across the screen with a counter-attack that ground-bounces. [If not, she disappears after a few seconds.]

Name: Carol
Debuted in: Guilty Crown: Lost Christmas
Voice Actor: Kana Asumi

A beautiful girl with a strange mood. A partner of Scrooge, who has escaped from the same facility as her. Although she has been deemed a "failed product", Carol is the only one who is resistant to the crystallization effect of Scrooge's right hand; however, her Void does not have a definite form, and takes a different shape each time Scrooge draws it out.

Assist Technique: The Chalice Void
Startup - 25 seconds
Recovery - 70 seconds (on cancel) / 25 seconds (in neutral)

Carol summons a swarm of locusts; after a while, they cross the screen, dealing lots of hits and lots of damage.

Name: Sone Miyuki
Debuted in: Kimi to Kanojo to Kanojo no Koi.
Voice Actor: Tezuka Maki

A smart and beautiful school idol. Has a vast array of talents, batting being one of them. She’s rarely seen without her bat, and can often be found at the town’s local batting center practicing her swings. Loves cats more than anything in the world despite being allergic to them.

Assist Technique: Perfect Swing
Startup - 20 seconds
Recovery - 15 seconds

Miyuki appears behind the opponent and swings her bat, sending them flying towards you.

Name: Mukou Aoi
Debuted in: Kimi to Kanojo to Kanojo no Koi.
Voice Actor: Sendou Mitsuki

Given that she’s a character who focuses on getting in contact with god through her chants of ‘touarururururu~’s, it’s no wonder that Aoi is someone whose presence isn’t noticed by others – or rather, ignored. A classmate of Shinichi and Miyuki’s, her brain is full of nothing but games. Poor at socializing, both Shinichi and Miyuki feel like she’s unable to draw a line between reality and VNs, having them seamlessly merge.

Assist Technique: World Modification
Startup - 0 seconds
Recovery - 75 seconds

Aoi "instantly" gives 1 free stock of Power gauge to both players.

Name: Super Sonico (ASSIST-NOT PLAYER)
Debuted in: Sonicomi, Nitro Super Sonic music festivals (as mascot)
Voice Actor: Super Sonico

A university student who works as a gravure model and aspires to become a rock star. She performs as a member of the girl band "First Cosmic Velocity", being its guitarist and vocalist.
She is the main villain of Nitroplus in general, wishing to destroy everything that is good about it.

Assist Technique: We are First Cosmic Velocity!
Startup - 20 seconds
Recovery - N/A

Sonico and her band start playing music, only going away when the round ends. They produce small items that can be picked up by both players.

Green: restores 300 health
Orange: restores 1/6 of a single Power gauge stock
Red: boosts attack by 3%
Blue: boosts defense by 3%
Purple: boosts attack and defense by 1%


[In case you were wondering, YES you can still use your other assist even with Sonico active, though Sonico never leaves until the end of the round.]

Name: Yoguruma Mugen
Debuted in: D.Y.N.FREAKS
Voice Actor: Shiori Izawa

A magic user who has escaped from the Asylum medical institution to prevent "Hellhazard". Her left eye belongs to Yog-Sothoth himself, allowing her to manipulate causality at will.

Assist Technique: Fist of Yog-Sothoth
Startup - 11 seconds
Recovery - 25 seconds

Two circular effects occur in the middle of the screen, and after a moment the effects turn into an attack that can hit both players. Has guard crush properties.

[Repeat - IT HITS BOTH PLAYERS]

Name: Mitsurugi Yoishi
Debuted in: Phenomeno
Voice Actor: Fumiko Orikasa

A 16-year-old schoolgirl who frequents an occult website "Ikaigabuchi". Although she has great curiosity that allows her to explore various occult spots without fear, she has a habit of vomiting when she feels malice.

Assist Technique: Vomit
Startup - 11 seconds
Recovery - 25 seconds (on cancel) / 15 seconds (in neutral)

A black cloud comes from the opponent’s side of the screen. On hit or guard, it removes the opponent’s ability to jump.

Name: Alushia
Debuted in: Hakubou no Dendoushi
Voice Actor: Nozomi Yamamoto

A child of an elf and a human, she is shunned by the elven race due to being of impure blood. She has been betrayed by humans many times, as well, making it very difficult for her to rely on anyone.

Assist Technique: Great-Axe Slash
Startup - 15 seconds
Recovery - 80 seconds (on cancel) / 60 seconds (in neutral)
Alushia falls from above with her great-axe and combos the opponent. Massive damage and hitstun.

Strategy: [Not mine.]

Alushia attacks 4 times. The first 3 all happen fairly quickly and will usually combo even if proration in the combo is fairly high. However, the 4th and final hit has extra startup, and does the most damage (notice the blood hitspark). Make sure to add an extra hit between the 3rd and 4th hits so that you can combo properly.

Name: Angela Balzac
Debuted in: Rakuen Tsuihou: Expelled from Paradise
Voice Actor: Rie Kugimiya

Angela was raised in a Matrix-like computer system on a space station orbiting a post-apocalyptic Earth. After a hacker from the devastated planet Earth below breaks into the system, she is tasked with finding and stopping the hacker in the real world. To do this, she is transferred into a clone body, given a mech, and told to meet up with an agent living on Earth named Dingo.

Assist Technique: Automatic Smartfire
Startup - 30 seconds
Recovery - 40 seconds

Sky lazers. Jump -> Homes to the opponent -> Lazer attack.

Strategy: [Not mine.]

Since she takes a really long time to start attacking, you’ll need a setup to combo into it.
[Cut her some slack since she's firing from orbit.]

Name: Hougyou Ilia
Debuted in: Tokyo Necro
Voice Actor: Yuzuhara Miu

A cheerful, easygoing girl who has become the target of necromancers. Despite having lost a portion of her memories, she is well-versed in 20th century otaku culture, often speaking in outdated manner because of that.

Assist Technique: Smart Material
Startup - 9 seconds
Recovery - 30 seconds (on cancel), 15 seconds (in neutral)

Ilia makes ice blocks appear from under the ground, launching the opponent. The ice then remains on the screen for a while, blocking character movement (but not projectiles).

Name: Tsunemori Akane
Debuted in: PSYCHO-PASS
Voice Actor: Hanazawa Kana

The newly assigned Inspector of Unit 1. Considered a model citizen due to her ever calm demeanor and for passing the exams with the highest score for employment on several public sectors and private corporations. She decided to join the police due to being the only place where no one obtained a score as high as hers, thus she believes to be able to do something there that no one else can.

Assist Technique: Dominator
Startup - 11 seconds
Recovery - 20 seconds (on cancel) / 15 seconds (in neutral)

Akane shoots a beam from her Dominator gun. By default, she shoots a Paralyzer, putting the opponent in a crumple state on ground hit. If the opponent's health is red, she shoots an Eliminator instead, increasing its start-up, but dealing more damage over two hits with a larger hitbox.

Name: Amy
Debuted in: Suisei no Gargantia
Voice Actor: Kanemoto Hisako

A young girl who works as a messenger on the great fleet of Gargantia. She possesses great curiosity and never loses her cheerful smile.

Assist Technique: Messenger
Startup - 9 seconds
Recovery - 25 seconds

Amy flies from one side of the screen to the other and back, three times in total. On hit or block, she falls down her glider, pre-emptively ending her activation.

[She's good for keeping enemies out of the air, but she's also pretty easy to dodge.]

Name: Takeya Yuki
Debuted in: Gakkougurashi!!
Voice Actor: Minase Inori

A cheerful high school girl who loves school to the point of creating a "School Live Club" and spending the nights in the school building. However, she is unaware of the fact that the daily life she loves so much has been long gone.

Assist Technique: Everyone in the Class
Startup - 20 seconds
Recovery - 30 seconds

Yuki runs forward and trips, hitting the opponent in the process. After a while, a wave of zombies follows after her. Although there is a lot of them, they can be hit by the opponent, making them disappear right away.

That's the simple stuff. Hopefully this guide can at least help you formulate more strategies, and maybe you'll share what you come up with with others by posting your own guides down the line. Till then, good luck! MERRY CHRISTMAS! HAPPY HOLIDAYS! HAPPY NEW YEAR!