"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 any weapons while in mid-air.

However, using a quick "Guard-cancel" right after the start of the jump, you can swing your melee weapon.
Timing the attack right, and you can get a fancy market-garden kill.

Just remember, heavy swings need much more time to prepare, so you need to start the attack way before you land.

1. Start the second charge-up attack as Massive
2. Right as you are above ground, press the "Right mouse" button to cancel
3. As soon as you start falling down, time your heavy melee swing(usually just before/after you start falling)"