is that a Pie symbol on his forhead?

It's a purposefully ambiguous symbol. It's similar to quite a few different symbols. There's the pi sign, yeah... Then there's also a Hebrew symbol and some Japanese kanji. They're all applicable. I'll leave it up to the individuals to discern how it applies to him, but there is a point toward the end where the meaning of the symbol within the Battle Holiday world is exposed. Sorry. Prolly a longer answer than you wanted. :D

haha the eye patch reminds me of KillBill hehe

HOLY HELL THATS AWSOME!

Thank you much.