Lightning grenade is not a one hit kill Trip mine requires great placement, is the easiest grenade to see in the game, and leaves people with a little bit of health left, so it is not even a one hit unless someone runs low armor, which is very few people. Fire bolt instantly hits everyone in a huge radius, is extremely easy to hit with, makes it so one hit from anything confirms the kill, and burn damage means that even if you don't finish them they will be forced to stay out of the fight for an extremely long time.