There are many ways to say something looks _____ : N + 처럼 보이다 - e.g. 완전히 다른 사람처럼 보이네요. - You look like a completely different person. V + -ㄴ/는/은/ㄹ/을 것 같다 - e.g. 비가 올 것 같아요. - It looks like it's going to rain / It seems like it is going to rain. To answer your original question though, I would just say something like "오빠는 눈이 엉망이라도 아직도 잘 생겼어요!" (Even though your eye is a mess, you're still handsome!). I wouldn't worry about trying to translate each word verbatim, because it can often sound unnatural.

i think in this sentence terrible means 'quite ugly' so you can say 너 눈은 진짜 못생겼지만 얼굴은 잘생겼어 generally if people say terrible for someone's appearance. it means really ugly