Bounstrike shoots a flare when used. Upon resting, 8 sillyballs in an organized line falls down from the sky and bounces around until they hit someone or explode after a certain time (specifically after the balls have bounced off the ground a combined total of 30 times). Bounstrike and its stronger variations can be surprisingly effective if you can work well and combo it with teammates. Damage per projectile is based on the distance between you and the enemy tank.
Bounstream reduces the maximum damage done, but adds in significantly more sillyballs, resulting in higher average damage done. They bounce off the ground up to 40 times before exploding on impact.
Bounstorm adds in a large amount of sillyballs to the point where the sillyballs are touching side by side. Again, maximum damage done is reduced due to the increased amount of sillyballs. They bounce off the ground up to 50 times before exploding on impact.