With Legendaries: Darkrai, Weavile, Zoroark, Honchkrow, Tyranitar without Sand Stream (dream world), Drapion
Without: Everybody except Darkrai, who is replaced by Houndoom.
Darkrai: The only Pokemon that can beat Arceus with regularity. It should know:
Dark Void
Nasty Plot
Dark Pulse
Focus Blast
Weavile: A sweeper. It should know:
Ice Punch
Brick Break
Night Slash
Fake Out
Zoroark: Use the moveset I gave on this site.
Honchkrow: A hard-hitting Pokemon. It should know:
Brave Bird
Sucker Punch
Perish Song
Mean Look
Tyranitar: While the ability Tension isn't as good as Sand Stream, in this case it is. Tyranitar might not be as good without Sand Stream, but this makes him a better choice for this team. He still has great stats afterall. It should know:
Stone Edge
Crunch
Earthquake
Flamethrower
Drapion: Only one weakness. Should know:
Night Slash
Cross Poison
Earthquake
Ice Fang
Houndoom: Should know:
Flamethrower
Dark Pulse
Nasty Plot
Toxic