Hero vs Roy

Focus on keepaway. Roy in the clinch is one of the most dangerous characters in the game, so use neutral-B to keep him at a distance and side-B when he gets too close.

Whenever you have room to breathe, focus on your down-B projectiles rather than buffs. Whack and Sizz/Sizzle will be good keepaways, while Kacrackle Slash and Thwack will be good close punishes.

Don't forget a good way to counter roy is spot dodge to level 1 up b. Not a lot of damage but it can give you advantage.