To defeat ritual deckz, reach stage/mission 33 so you won't have to deal with all those ritual deckz anymore. In fact, you might not be able see them ever again, which is what you probably wanted. AM I A GENIUS OR WHAT? (͡ ͡° ͜ つ ͡͡°)
Use a ritual deck yourself.
The strength of rituals is that they can quite fast summon strong monsters and you mostly can do nothing about it. The answer is summoning or buffing something over 2000 fast or decreasing your opponet's attack enough also fast.
Easy, Black Horus dragon works if you can level it up quickly. Lv 7 can cancel trap cards. Also, I’ve used a blue eyes summoning deck with restart and a silent magician deck and have yet to lose. Fusion decks work okay as well. Traps such as curse of Anubis and floodgate trap hole work great