Pretty much everything is viable in ASB, and a lot of things have the potential to be really good. However, if I were to guide you more specifically, Steel mons and CAP's are quite strong; therefore, Kitsunoh is probably the best Pokemon ever.
My CAP ASB Team
[23:35] <Jesseus> <Glacier> im not frunk
[23:36] <Glacier> jessues whered the d go
[21:25] <Pwnemon> look at kax vs cmfp, iar vs cmfp, pwnemon vs cmfp
[21:25] <Pwnemon> none of us had teams that by rights should have lost
[21:25] <Pwnemon> but he's cm fucking p