I am going to try the VGC (Video Game Championships) and I want a Blaziken with the moves Blaze Kick, Sky-Uppercut, Slash, and Flamethrower. I already have Flamethrower. If I evolve Combusken and level up Blaziken to 59 to learn Sky-Uppercut and, when I battle, it reduced to lv 50, does it still have that attack?
If you're asking if moves past level 50 stay on Pokémon even if it is reduced to level 50, then YES.