Barca

Barca is an ice elf that appeared in the second season of Solo Leveling as the final boss of the red gate dungeon. He is a sadistic and egoistic S-rank magical beast, intelligent compared to its kind. He has blue skin and white hair and controls an army of elves.

He was able to defeat Kim Chul's squad and when the leader ran away he ended up facing Jin-woo. He had the upper hand at first, but was defeated after Jin-woo's shadow army defeated Barca's army and with the help of Iron and Igris. Jin-woo was not able to convert Barca to a shadow soldier.
(Source: Solo Leveling Wiki)