Spoons (M) @ Alakazite
Trait: (N) Inner Focus (M.E.) Trace
EVs: 252 SpA/ 252 Spd/ 4 SpD
Alakazam is definitely made to be a sweeper. I personally use him as a Mega, but I recently found out about the whole Life Orb and Magic Guard thing, and I do think that's a good set up, but I'm just gonna talk about my set up.
Mega Alakazam is pretty underrated, as he is completely better than my Mega Gengar stat wise. Psychic or Psyshock can be your STAB move, depending on which you consider is a more useful move. Shadow Ball is to cover your ghost weakness. Dazzling Gleam or Focus Blast can be used to cover your dark weakness. You can choose Dazzling Gleam, Focus Blast, or Energy Ball for your last two slots, but I say to junk Focus Blast as it's pretty unreliable. Trace is a pretty solid ability, as it can be a game changer, or be completely useless. If you gain an ability you may not like, switching out is still an option, as that restarts the Trace ability. Also, don't try to use Recover, Calm Mind, or any move that doesn't actually attack, as Alakazam can't take a single hit. Also, I do consider trying to get a Modest nature instead of Rash. I was to lazy to keep going for Modest.