Misspelling of きをつけて. Since o is written as を when used as a particle.

骨学: osteology

(informal, cutesy) Alternative form of かわいい (kawaii)

無力: powerlessness

現実的: pragmatic, down-to-earth

巨大: enormousness

巨大: huge, gigantic, very big

a place of worship / 城: castle

(archaic) second person personal pronoun: you

cling to, adhere, stick fast / keep close to someone, follow / date, go out, be involved with someone romantically