Mwahahaha... Just like Mega Aerodactyl, Mega Absol is a beast. :)
You can check out Absol's Data HERE
You can LITERALLY Annoy the [Censored] out of people who use Prankster Pokemon or Status move users with this thing...
Note Absol is only in the Field egg group, as you may have to breed Pokemon to get the moveset I use.
Special Annoyance and Sweeper
Absol (ABSOLutelyNO) @ Absolite
Pressure (You won't need this technically as you will immediately mega evolve Absol on the first turn.)
Timid Nature (+Speed, -Attack)
EV's : +252 SpA, +252 SPE, +4 SpD
Detect, since it takes a full turn to get Mega Absol's useful speed.
Hex, To damage the would be staller, as that staller is using status condition inducing moves. Decently self expanatory. (Not Absol can ONLY learn this through breeding with a compatible Pokemon in the same egg group. Thankfully this is easy, as Vulpix learns Hex through Leveling up, and they are in the same egg group.
Dark Pulse, STAB, and Flinch chance.
Ice Beam, yeah I know it may have surprised you, as it surprised me too, but Absol can learn the TM for Ice Beam. Perfect for covering Bug types, especially Speed Boost Sweeper Yanmega, which Mega Absol is succeptible to...