Idea battling a boss

Mewtwo: also, for people to defeat mewtwo its easy. and yes but if u want do it alone i recommend you the idea of: Use your most stronger poke, i mean your poke that its level max. if you dont have yet, try using charizard and using its mega stone Y too, for better chance of defeat it. Regice: this boss its more stronger and its battle its more hard to defeat than mewtwo boss. try using a fire type poke level 50-70, I recommend you Charizard,   and use its flamethrower move for better chance to defeat it. Regirock: ⚠️WARNING: FIGHTING REGIROCK REQUIRES ALREADY HAVING REGICE. regirock its more hard than regice. try using a flying type poke level 70-90    and use a move for example if you have a poke that has the move Rock smash, use the poke and use its rock smash to regirock for better chance to defeat it. Registeel: ⚠️ WARNING: FIGHTING REGISTEEL REQUIRES ALREADY HAVING REGIROCK. registeel its like easy,      Use a Pyshic type poke and use it for better chance of defeat it. Regigigas: ⚠️ WARNING: FIGHTING REGIGICAS REQUIRES HAVING ALL REGI TITANS. regigigas its the most hard in the game. use a normal type or a fire type poke better chance to defeat it. also, just players that has all the regi titans can help you.