CREAM_93: The problem with Cresselia is that she gives the team a big Tyranitar weakness if I replace Donphan for her. Azelf, Rotom-h and Cresselia are all destroyed by Pursuit or Crunch. Even with Infernaple being able to revenge kill, I lose the sunligth and a sunny day user. With Ice Shard on Donphan I don't fear DD mence much. Cresselia is an excellent wall in Sunny Day teams, but putting her in my team gives me problems with Tyranitar.
Joshe: I tested Nasty Plot Infernape while ago but the mixed set gave me better results. I usually don't have time to set-up Nasty Plot and without Close Combat Blissey walls me easily. On the other hand, Vacuum Wave gives me a better way to counter ScarfTran and I don't have to worry with Lucario's Extremespeed. I'm once tested Hitmontop for using priority moves because it could counter Tyranitar and could work as a good Sunny Day user. I think a Shadow Sneak or Sucker Punch user could be really useful since it can help me against Latias and Starmie.
pokefan0: Specmence doesn't give much trouble. Without any speed boost, Infernape, Donphan or Heatran can revenge kill it easily. DD Mence are much more dangerous for my team.
Thank you everybody for the comments and sugestions. I'm testing new pokemons and moves for this team. =)