Which Is Better?

So I just got the Tremorback Recipe and I was wondering if it would be better to combine them or leave my Lvl. 99 Thunderback and Lvl. ?? Brachio-Thing as two separate arks. Any suggestions?

Fuse them

It gets like incredibly higher stats, right? I just wanna make sure.

Yes he does

Ok thanks.

You welcome

Yep , thunderback is Much better