Please note that Regigigas is capable of causing massive damage.
1) Each step he takes does 18 damage if you collide
2) One of his !!! move will make 4 obstacle on the ground, rendering any looping almost impossible. Wait till them disappear then resume looping. 8 damage if collided.
3) Another involving a rock shower and an X on the ground, causing 8 damage.
4) His !! move is Hyper Beam, deals 18 damage if hit. Move your line away from the direction it's facing.
5) His ! move is Focus Punch, deals 18 damage if hit. Move your line away from the direction it's facing.
6) After 1/2 bar is filled. Rocks will drop as he walks, deal 8 damage if hit.