The strongest one you can actually punch, yes. There are a small number of antagonists that exist outside of time and space entirely and have no physical forms that can be physically interacted with, but they don't really count because the only way to fight them is permission from the author. At that point, the fact that you are in a mecha is totally fucking irrelevant, you are just a wizard who has robot legs to do his walking for him.
Muge isn't all that great. While it's hard to make him STAY dead, he's not exactly the most durable evil overlord.
>Isn't the bad guy from Godmars also freaking powerful?
He is, but his real issue is they can't seem to decide what he is. First he's just an evil alien overlord then just an infected guy from some space evil creature, then he's Satan or something who lives in the son and tortures the souls of the dead and then in the finale all the various minions he's sent since fuse back into him somehow.
>is literally invincible
>the only reason the protags even lived is because they impressed him enough with their resolve to leave their dimension alone
Yeah, definitely an overpowered one.
>He is, but his real issue is they can't seem to decide what he is.
HE IS JUSTICE
>He can even control reality and all the fluff in his own dimension.
In his own dimension, yes. And I wouldn't say he can control reality fully even there, considering the amount of time the Dankuuken took to hit him where it was entirely in midair (and the things it flew through).
He's a strong antagonist, yes. Anti-Spiral strong, no.
I'm watching that show now. GOOD GOD THE CGI IS LITERALLY BLINDING.