
Zihark is a playable character introduced in the Fire Emblem game series created by Nintendo, first introduced in Path of Radiance (FE9). Introduced as an recruitable enemy mercenary, he is later discovered to hail from the nation of Daein in the game's sequel, Radiant Dawn (FE10).
He appears in several other games including a bonus DLC character in Awakening (FE13), Heroes (spin-off gacha game), and in the (discontinued) FE trading card series Cipher as of writing.
A compiled set of Zihark images from PoR/RD in one image for drawing/meta reference. Right click and open in new tab for original high resolution.

A close-up high-resolution shot of Zihark in an old promotional artwork. Right click and open in a new tab for highest resolution.

Rita Suzuki (who draws official Fire Emblem art for many games) once drew work of Zihark in celelbration of the trading card games. You can see it below.

Zihark's name in Japanese is "ツイハーク"; likely derived from Tsui Hark, a Hong Kong filmmaker. A pre-release screenshot from E3 2004 has Zihark's name as ツィハーク Tsihāku instead of the final game's ツイハーク Tsuihāku. In Heroes, his traditional Chinese name is "吉哈克".
Though Zihark's girlfriend left from pressure in the English version, the original Japanese version does not elaborate on what happened to her. The artbook confirms that she was killed.
Zihark was briefly shown in several screenshots of a beta version of "Path of Radiance" made for the N64 at E3 2004. Preserved screenshots can be seen below. Development lingered long enough it was decided that game was to be made for the Gamecube one generation later.
Zihark is one of the few recruited units who can defect from the player's side to the enemy side when chosen to speak with the enemy, with Jill being the other.