Nice, I was thinking of Ononokosu too before you posted that ^^
A DD set with Earthquake, Dragon Claw / Outrage, DD and Taunt.
Since Skarmory flat out beats this set, I'm planning to team it up with Magnet Pull Magnezone, probably something like Substitute, Thunderbolt, HP Grass / HP Ice, Explosion.
For your lead, I'm thinking of Agirudaa, having 145 base speed, and access to Taunt and Spikes, which could really help Ononokosu in sweeping. That is all I have so far.
EDIT: Never mind, you don't really lose to Skarmory because you have Taunt. However, it still will be attacking you with Brave Bird while you can't hurt it, so after you've used Taunt, switch in Magnezone, set up Sub, and THUNDERBOLT!