Forum:Wyvern, is it worth it?

Beside being awesome looking once he's in 5* form. But I have him in 4* now and he seem kind suk. I mean his special is so weak unless I'm not understanding it. So my question is, is it worth leveling him at all? Right now my party consist of God Knight Will and 2x Queen Luna. So I figure having him on my team would help in the long run. But he doesn't see strong. Any suggestion?