A female that has the qualities or characteristics of one who is of the male gender. A truly rare alpha female that becomes the 'man' in the relationship.
"dude after sex, she didn't want to cuddle last night. she's freaking mantastic."
Beyond positive description in any other form. Flawless to the point where the very flaw itself is true perfection. No mere mortal can inherit this into his/her being, except Mantastic Dan.
* GOD was kicked by Mantastic_Dan (*SWISH!* "And so you are felled!")