Short answer: Yes, but only if you plan to do postgame stuff.
Long answer: Yes, and here are the useful ones for different things throughout the game:
Usalia - Hell Mode is useful as it maxes all Hell Modes for all characters when used (on map)
Melodia - Great innate evility, an extra Maiko due to Passion Approach
Flonne - Good passable evility to block status effects
Bieko - Good innate evility
Pleinair - Good innate evility, good passable evilities, good Hell Mode, Pleinair
Etna - Good passable evility (Dominant Smile)
Valvatorez - Good passable evility (I forget the name, but the prinny one)
Fooka - Good passable evility (Prinny Hat) (they don't like her real name on here, lol)
Rozalin - Great innate evility
Adell - Best damage dealer in the game
Desco - Good passable evility (the one where you lower resistances)
Axel - Good passable evility for lazy people (the one that doubles your stats if solo)
Artina - Great innate evility, good passable evility if doing HP stuff
Girl Laharl - Good passable evility (Hyperfocus)
Seraphina - Good passable evility (HL Power)
Mao - Good passable evility (the bonus to item reincarnation one)
Zed - Good passable evility (reincarnation one)
Raspberyl - Good passable evility (IW one and Innocent Squad one)

Originally posted by inviso87:

Short answer: Yes, but only if you plan to do postgame stuff.
Long answer: Yes, and here are the useful ones for different things throughout the game:
Usalia - Hell Mode is useful as it maxes all Hell Modes for all characters when used (on map)
Melodia - Great innate evility, an extra Maiko due to Passion Approach
Flonne - Good passable evility to block status effects
Bieko - Good innate evility
Pleinair - Good innate evility, good passable evilities, good Hell Mode, Pleinair
Etna - Good passable evility (Dominant Smile)
Valvatorez - Good passable evility (I forget the name, but the prinny one)
Fooka - Good passable evility (Prinny Hat) (they don't like her real name on here, lol)
Rozalin - Great innate evility
Adell - Best damage dealer in the game
Desco - Good passable evility (the one where you lower resistances)
Axel - Good passable evility for lazy people (the one that doubles your stats if solo)
Artina - Great innate evility, good passable evility if doing HP stuff
Girl Laharl - Good passable evility (Hyperfocus)
Seraphina - Good passable evility (HL Power)
Mao - Good passable evility (the bonus to item reincarnation one)
Zed - Good passable evility (reincarnation one)
Raspberyl - Good passable evility (IW one and Innocent Squad one)

I want to do a followup question, very very specific ones: If someone uses cheats to get said evility.... is there anything else that's useful?

Please keep in mind that no, people don't wish to get ripped of. Aka you need to pay to get access for evility. And also, this doesn't include anyone buying a dlc because of their favourite character. So the idea of my question, other then for those evility, is there anything that justify the price tag? Because good skills behind a paywall is a typical manipulation, aka emotional black mail, "you want this? oh well, you need to pay! You don't? well spend hours and hours and even more hours since we designed the game in a way to make you want those skills".

Originally posted by Green Cat:

Originally posted by inviso87:

Short answer: Yes, but only if you plan to do postgame stuff.
Long answer: Yes, and here are the useful ones for different things throughout the game:
Usalia - Hell Mode is useful as it maxes all Hell Modes for all characters when used (on map)
Melodia - Great innate evility, an extra Maiko due to Passion Approach
Flonne - Good passable evility to block status effects
Bieko - Good innate evility
Pleinair - Good innate evility, good passable evilities, good Hell Mode, Pleinair
Etna - Good passable evility (Dominant Smile)
Valvatorez - Good passable evility (I forget the name, but the prinny one)
Fooka - Good passable evility (Prinny Hat) (they don't like her real name on here, lol)
Rozalin - Great innate evility
Adell - Best damage dealer in the game
Desco - Good passable evility (the one where you lower resistances)
Axel - Good passable evility for lazy people (the one that doubles your stats if solo)
Artina - Great innate evility, good passable evility if doing HP stuff
Girl Laharl - Good passable evility (Hyperfocus)
Seraphina - Good passable evility (HL Power)
Mao - Good passable evility (the bonus to item reincarnation one)
Zed - Good passable evility (reincarnation one)
Raspberyl - Good passable evility (IW one and Innocent Squad one)

I want to do a followup question, very very specific ones: If someone uses cheats to get said evility.... is there anything else that's useful?

Please keep in mind that no, people don't wish to get ripped of. Aka you need to pay to get access for evility. And also, this doesn't include anyone buying a dlc because of their favourite character. So the idea of my question, other then for those evility, is there anything that justify the price tag? Because good skills behind a paywall is a typical manipulation, aka emotional black mail, "you want this? oh well, you need to pay! You don't? well spend hours and hours and even more hours since we designed the game in a way to make you want those skills".

You can do everything without DLC in the game, just less efficiently.

Depends on what you mean by useful.

Usalia, Melodia, Bieko, Rozalin, and Artina are incredibly useful against Carnage Baal and for the infinite gas method. Usalia for her Hell Mode, Melodia for passive boost and Passion Approach, Bieko for innate evility boosting damage, Rozalin for innate evility, and Artina for her innate evility as well all providing extra boosts to output (damage, attack power, etc)

Flonne is useful for PvP b/c of her passable evility, as is Axel.

Desco is helpful if you're struggling against normal Baal.

Girl Laharl gives a subtle boost with Hyperfocus.

Fooka, Etna, Seraphina, and Zed are good for stat boosts.

Raspberyl and Mao are useful for item world stuff.

Adell is best damage dealer.

They all have their own things that make them viable, but again, none are necessary to complete anything in the game. Carnage Baal is defeatable without any DLC, but you need to do more setting up and more preparing to do so.