How is your page supposed to prove anything?
No fucking shit he would be scared of dying, he's just a normal human, you would be shitting in your pants if Faust open your punk ass bitch up too.
Even after Yoh pretends to be mad at him to not put him in harm's way Manta still decides to go to Izumo after him.
I can see why people may be annoyed at him being a comic releif but give me a fucking break you autist, he is not a coward, not even close. For how fucking puny he is, he has some guts.
Your punk ass bitch on the other hand? You probably would have dumped Yoh and made sure you never interacted with him again.