Someone who is unnaturally strong in his own right. Someone who acts or looks very cool.
Basically you can call "Klark" a person who can be looked upon.
Examples would be ones like Batman or Superman. Although origin of this word is unknown, but it may very well be a derivative from Superman's first name "Clark" Kent.
This word is rarely applicable to real people and is often used to praise fictional characters in films or anime.
Anime examples are "
WhiteBeard" from "One Piece", "
Yamamoto Genryūsai" from bleach, "Sarutobi Hiruzen" from "Naruto".
--Someone
beats the shit out of 20 man--
What a Klark!
--Guy outsmarts everyone and comes on top--
What a Klark is he,
god dammit!