i'm in your conscience
As long as you're not changing it too much to where it's not recognizable haha. The general rules are that you pick a generation (or you can do all gens) and get a team of 6 put together (I asked the community for my Pokemon, which you can see if you check my blog and look at the Unova Hall of Fame section) and use them to beat the Elite Four, thus getting into the Hall of Fame. You use only fully evolved forms, however you could use all Pokemon including NFE if you want. When doing it by generation, I include baby Pokemon that were introduced (using Wynaut for gen III HoF) and using Pokemon that were previously stand alone (Scyther in a gen I HoF). You can't use the E4 to grind levels, obviously.
I hope that makes sense? It's almost midnight lmfao.