Making a new important NPC

My thought is something liek a higher Elite Four and higher champion. For instance, these would be their own individual group, having instead of four members, seven. Then you would have the champion who would be extraordinarily powerful. Why? Because they would have phases. Phase 1: Ordinary fight, champion has one Pokemon for each gimmick though (You can also use multiple gimmicks), Phase 2: Champion has a seventh Pokemon (You don't get to heal) this is a mega, Phase 3: They pull out a box art legendary to fight you with, Phase 4: They end with a grand finale, using a mega legendary (This could be a new mega, Mega Hoopa for instance). What do you think?

Can I make one too? Actually, I think I've already began doing that… You may or may not understand what I mean.