I've been using Onoki since Kage Treasure came out. The lineup that works for me and that became my main team for fire main is with Tobi and Shurado.

Now this is a full glass cannon team, meaning less defense and full on offense. However, the power it contains with the support of Onoki's barrier and passive buff of an extra attack is just awesome.

This lineup works best if you have higher initiative than your opponent.
Check out the Plunders that I've done using this lineup. Fighting players with 1K-3K BP higher than me.
https://www.youtube.com/playlist?list=PLgB9krDf57rRVqIDirFwAi9cxrfPicJ3J

Also, I use Onoki for Ninetails Invasion because he is that awesome.