Here's another character suggestion:
Engineer
Appearance: Engineer is a male human with a robot arm. He wears two pairs of goggles. (One worn on his forehead, one on his eyes) He also wears a bandanna.
Weapon: Engineer Wrench- the engineer wrench is a wrench that, when swung, can extend if you click again. It also does the damage of one and a half wrenches.
Passive: Gets followed by a snow tank with a green eye. The tank will take out enemies for free. The engineer has 8 health, but takes 150% projectile damage. (Always round down, like Rebel's portal healing) If a tank dies, your max health goes down by 2. A new tank spawns in the next level. The tank's projectile type is random but is always low tier. The tank tears through any terrain -like hammerhead- and always stays close behind you. You don't die or get damaged if you get caught in the death explosion, but enemies will. You also gain 1 max health after every level.
Active: Hop in the tank. It takes five seconds to get in the tank and can only be used one per area. While in the tank, you have 20 health and infinite ammo. You have a whole minute to use the tank. Your projectile type is that of that tank. If the tank dies with you in it, the tank explodes and Engineer dies. If you survive, you don't get the AI tank until the next area. (Unless it's a one level area)
Throne Butt: Tank respawns in the next area, no matter the level count. It also has higher tier projectiles.
Ultra A- Abiotic Friends: A new Tank spawns every level, but you still only get one active per area. (Even 1 level areas now)
Ultra B- Driver's License: Hop in the tank every level, but the tank only has 10 health. You don't die when it dies though; your max health is only subtracted by 4.
Ultra C- Powerful Turret: High tier projectiles with 150% the fire rate. It also can now shoot out two projectiles at once like Steroids.
Ultra D- Golden Tank- Shoot a missile every 5 seconds and blow up larger, neither of which damage the player. Also, Golden Tank has double HP. But now it takes 10 seconds to get in the tank.