Parallax Entity Vs Mephisto

Who wins?

In and of itself? I'd say Mephisto. In a good host, I'd say Parallax.

parallax might take over mephesto?

I'm not sure if Mephisto would be the right type of host for the fear bug. Remember, Mephisto also thrives on inflicting fear upon other characters. That's not normally the 'kind' of character/mindset the bug goes for.

The entire yellow lantern thing was about guys who instilled fear on others. and parallax was part of that. I think mephesto would win in his own realm if he wasnt an idiot