And the last timeSupernaturalfans saw him, he admitted just how much those mistakes have stuck with him.

His past failures haunt him, and that will continue into the final two episodes of season 12.

I think that mindset has been driving Castiel for an incredibly long time, Misha Collins says.

All Along the Watchtower

Credit: Dean Buscher/The CW

We get into that no matter what the cost mode again in really stark relief in the finale.

Furthermore, Collins says, There are going to be some fairly epic consequences in the season finale.

One bit of good news?

Castiels decision to defend Kelly wont put him at odds with the Winchesters now that Lucifers free.

The band actually does get back together at the end, Collins says.

Were all fighting against a common enemy at the end.

Supernaturalairs its final two episodes Thursday at 8 p.m.

ET on The CW.