"As Massive, you can jump high in the air with your second charge-up attack.
This normally works as a moving tool, as you cannot use/switch any weapons while in mid-air.

However, using a quick "Guard-cancel" right after the start of the jump, you can switch to your side-weapon.
Timing the attack right, and you even shoot that gun while mid-air.

You can even use this trick by jumping over walls or peaking over high obstacles, which makes explosive weapons a pretty good option.

1. Start the second charge-up attack as Massive
2. Right as you are above ground, press the "Right mouse" button to cancel
3. Quickly press "Tab" to switch to your side-weapon(ranged), and shoot it as you are falling"