[Jotaku]

When your gauge is full and you have a weapon, and there is an enemy behind you, then first you can shot the enemy behind and then you use ultimate skill of that weapon that costs gauge as soon as you used it to enemy behind.

This trick works the best with rocket launcher the most, because it just lock down your enemy by one hit, and it has range, and ultimate skill goes front side permanently until it hits your enemy in front, like a guided missile.