Typically, something that is hellka is so astoundingly great it could cause one's mind to implode and explode at the same time.
As a noun, hellka refers to the mythical beast that was once said to terrorize villages 'cross the countryside.
Hellka is derived from the latin hellkos (meaning large demon bird of death).
"Dude, your liver just got hellka eaten."
"That party was hellka cool."
"Hellka Hellka sikka sikka gnar gnar hyphy!"
"Yea, I gave her a hellka good time. What about you? Oh, You Ice Dragoned her? That's pretty messed up dude."