This is about Monster Hunter: Rise.

I have played a lot more World than Rise.
In World, I pretty much exclusively used the Insect Glaive and rarely used any other weapons. I utilised both air and ground extensively.
In Rise, I decided to limit myself. Use less Glaive, try other weapons.

Rise makes the aerial side of the glaive more... interesting because of Wirebugs.

A lot of this guide will be copy-pasted content from my old guide. In terms of movesets, there's little in the way of changes between the two games except Wirebugs and Switch Skills.

The Insect Glaive is still the most unique weapon in Monster Hunter.

As a weapon, it's comparable to the Dual Blades, Longsword, and Sword & Shield. It's a fast weapon that does slashing damage. The Glaive has limited ranged capabilities and no shield to assist. It's a fairly simple polearm, being little more than a stick.

There are three things that make the Glaive unique.

1. Bugs. The Glaive is the only weapon that has a Kinsect, a bug companion.
This is equipped as a second weapon and does damage by itself. It's used to extract essence from enemies.
Unlike in World, where this was an independent ally that could trigger blast/healing effects, the Kinsect has been weakened in Rise. Rather than just "mark and forget" strategies, you now have to be more active.

2. Essence. The Glaive uses essence to empower itself.
There are three types of these essences: Red, White, Orange.
Red Essence empowers your moveset, granting you a better moveset. You get this from the head and some special areas (Valstax's wings, for example).
White Essence makes you faster. You get this from the wings of most creatures, and the tail of others.
Orange Essence exists and generally just exists to give you the buff. You get this from the body.

Only Red Essence really matters for this guide.

3. Air. The Glaive has Aerial Combat capabilities that other weapons lack.
In World, it was the only weapon that could function in the air. In Rise, all weapons can get somewhat airborne, but none shine like the Glaive.

People will tell you to stay out of the air. Most guides will encourage staying groundborne. This guide will make the air your ally.

The Glaive doesn't have many contextual options in the air, and one of the options has basically been reduced to being useless.

Without the weapon drawn...

So, Rise adds Wirebugs. Wirebugs allow you to get airborne without having your weapon drawn.
You can't really do much without your weapon drawn, actually. There's no easy way to go from sheathed-aerial to drawn-aerial.
You can do landing strikes, but that's about all you've got here.
This isn't really Aerial Glaive. It's just using the wirebug.

Vault.

Vault is a simple move. You launch yourself up in the air like a professional pole-jumper. This is the most basic way of getting in the air and honestly, the best way most of the time.
You launch to a height that's about level with wings of most creatures. It's about the same as a single wirebug upwards.

Evade.

When you're in the air with your weapon drawn, you can do an evade. This shoots out a jet of air behind you. It's like rolling, but without any i-frames.
This lets you change directions on the fly (literally) and it's similar to when you're airborne with a wirebug, you're able to move in a different direction.

These are mobility options, not attacks.

Silkbind Vault

One of the new moves, and a way to get airborne.

With this move, you use one Wirebug to get airborne and do some midair slashes. You are basically 'airborne' during this move, allowing for midair evades and the other attacks.

This isn't a good move to use, just because of the wirebug usage.

You can use this in midair as well. With Training and Infinite Wirebug Usage, you get infinite height. Great for testing "does this move do this" stuff.

The REAL attacks

Depending on if you have Red Essence, you get one of two movesets. With Red you get a stronger moveset. Without Red you get a weaker moveset.

No-Red Jumping Slash

Still the worst move in your arsenal.

You do a single slash that does about the same damage as a grounded thrust. You're locked into the animation no matter what when you use this move. You can't evade or do another attack until you hit the ground.

If you're close to the ground when you use this, you do a slam attack that gives a lengthy landing delay. Otherwise, it's identical landing delay to anything else.

Never use this, only villains do that.

No-Red Jumping Advancing Slash

This is like a second evade. You can change direction when you use this move and it's like a triple-jump. It's actually fun to use, even if overshadowed by the wirebugs.
In World, this was about the only way to get any aerial mobility. In Rise, you've got wall-running and wirebugs to get around. It's nerfed my boi.
Actually Wirebugs out of combat add so much mobility that it's fun for other classes now.

In combat, this allows you to do a second vault. You will launch when you hit an enemy, allowing for the combo to reset. You can stay airborne for ages using this, by using: Vault -> Evade -> Advancing -> Evade -> Advancing.

Don't.

Red Strong Jumping Slash

My boi. My sweet, sweet boi. In World, this was my main way of landing. It would allow for you to ride on monsters rather easily, and it looked cool. As you can't ride in the same way, this function is less useful.

You do a long, descending twirl that hits multiple times. You get a lot of landing delay, but you can hit 2-4 times with this attack. It's still an effective way to land, just no longer the best one.

Red Strong Advancing Jumping Slash

This is the Aerial Glaive move.

You advance, twirling the glaive around you. You do multiple hits with little bites and when you finish, the last strike will vault you up. This means you can stay airborne for a while and do damage.

So, Rise adds Switch Skills.

Silkbind Vault is the biggest one, and was covered above. This is a way to get airborne and do some damage. Very nice, very cool. I'm not a fan.

However, there are two more Switch Skills worth mentioning for the Glaive.

First, is Skill 1.

Advancing Roundslash

This is the alternate Switch Skill 1. It changes your draw attack and another grounded move. This generally doesn't matter too much, pick whichever you like.

Except that you can use this attack to get airborne. As the description says, getting hit will get you airborne. This can be used as a way to dodge up into the air.

Don't rely on this.

Next is Skill 3.

Diving Wyvern

Return of the King.

This was a standard move in World. You pressed a button in the air to do a descending thrust. It was useful, and it was removed.

In Rise, it's a Switch Skill (3). It can be done in the air or on the ground.

On the ground, it launches you in the air and then you dive straight down. You can't interrupt, but you can use this to do a lot of damage. It allows for some interesting dodges, and tail cuts. Best wakeup move.

In the air, this plunges you straight down. It's not the fastest way of falling down, but it is the coolest. You will drop from your current height, which means this is faster if you're close to the ground.

So, everything that was true in World is true in Rise.

The Glaive can stick to climbable walls. The Glaive can be used to jump around. You can dance and move around and have fun getting to high areas with a vault.

However, Wirebugs exist now.

You can't wall-run while vaulting or using aerial glaive. You don't get the same height as a double or triple bug. You're better off just using wirebugs than using the aerial side of things.

Bah humbug, right?

As a Glaive fan, I'm happy.

Everyone gets increased mobility. That means a lot. It means that we all get to explore. We all get to experience the joy of vertical levels. Rather than being stuck on the ground, we all get to experience the wonder of the skies.

Sure, it's kinda a nerf. It's no longer something we get to experience that others don't.
But it's a great experience, and one that's worth sharing. The skies belong to no-one, not even the glaive users.

We'll just have to settle for being better in the air during combat, rather than in exploration.

Do not exclusively use Aerial Glaive.

If you can, a grounded combo is going to be better. This was true in World and it's still true now. For most of a fight, you're going to want to get openings for ground combos.

Aerial Glaive lowers your DPS by a significant amount. It's not as bad as it was in World, but it's still lowered. If you can learn grounded combos, you'll be better off.

For most of a fight, you want to be groundborne.
But there are advantages to being in the air.

Despite losing some DPS, there are some key elements of Aerial Glaive that make it a very useful tool to have. It's not your entire belt, but it's a tool you have.

Wing Breaks

The Aerial Glaive is the best way to break wings. If you need to collect wings, then you an use the Glaive to break the wings much easier than other monsters. This can also be used on the Serpent's Belly/Horns when they're flying. Other weapons struggle more with that.

Deflections

When you hit a monster without the right amount of sharpness, you will get deflected and stunned. Monsters also have armoured sections that can deflect attacks and that will interrupt your combo... And also you will probably get hit.

Aerial Glaive does not suffer deflections at all.

It doesn't matter if you're attacking heavily-armoured tanks or paper, you're going to get that attack off no matter what. A Raging Rajang's Forearms might as well be made of cardboard.

So, one of the big issues with the Aerial Glaive comes from knockback/knockdown.

When you get knocked down or hit by a special move, you're limited until you get back up.

If you're on the ground, the animation for standing up happens almost instantly.

If you're in the air, you need to land first.

Fighting a Daora, you can end up being in the air for ten seconds with nothing to do but watch yourself fall.

Moves that disable Wirebug recovers also make being in the air more dangerous. Getting hit by a Goss Harag's Ice Beam means you're going to probably take a follow-up hit.

If you're hit in the air, either directly or even accidentally, you're going to lose any benefit of being in the air. You're now just waiting to land.

If your wirebugs aren't disabled, then a wirebug recovery turns a monster's combo into a safe landing.

Aside from being the best way to land (with Diving Wyvern), Wirebugs to recover are important.

Take more care
in the air
if your wirebug's not there
else beware
for you fare
worse up there.

If you're in multiplayer, or in general, read the room. If they're fine with you being aerial, be aerial. If they're complaining, drop to the ground.

Wing-Breaking

If you want to get wings, be in the air.
It sounds simple, but it's actually the best part.
You can easily break wings, and get wing parts, when you're airborne. It's a lot easier than waiting for topples.

Mirewallking

If you don't have some way to traverse difficult terrain, you're going to be slowed down by water and mud and all that stuff.

When you're in the air, it doesn't matter if you're flying over solid ground or a lake of mud. You're going to be moving at a consistent speed. It's a lot easier to use if you don't have some way of subverting the mud.

Approaching

This is the reason to take to the air.

Strong Jumping Advancing Slash has a few properties.
It's Strong (the damage over the course of the attack is nice)
It's Jumping (airborne)
It's Advancing (you move towards the target)
It's a Slash (you can cut off parts)

When there's a distance between you and the target, you can use the air to approach. An aerial evade followed by a strong slash covers a lot of ground, and you're doing damage there.

If you want to advance on an enemy, there's generally few better ways to go about it. You can close the gap. Then land with either Strong Jumping Slash or Diving Wyvern.

Lack of Anti-Air

This was more applicable in World than in Rise, but it still is worth mentioning.
Because the Glaive is the only real airborne weapon, most monsters don't know how to deal with it.
Many attacks are grounded and will miss an air attack. If it's fighting a Buddy or an ally, then you're generally not going to be hit by the collateral attacks at all.

As of Rise, there are more attacks that can hit airborne targets. More ranged attacks include a strike up. This is generally avoidable with an evade/slash, but be careful.

Don't exclusively stay in the air.

There's not a lot in terms of damage loss, but if you can get a grounded combo then it's going to be better than an aerial combo.

Use being in the air as a tool to advance and engage foes. Use it as a tool to break the wings.

I've had a thousand hours of Glaive gameplay across World and Rise, and it's still a delicate balance. It's up to you to decide when to use it. Give it a try. Don't neglect it.

Make sure you've got Red Essence when you're airborne. Having a wirebug ready to evade is also useful.