We have many ways of saying this: nonetheless, he's my father nevertheless, he's my father even so, he's my father however, he is my father still, he is my father after all, he's my father
I was marked wrong for putting 'he's still my father' and the correct solution was shown as: He's but, my father. Where did that come from?
WordReference suggests though with the sense of "however" [and an archaic term withal , meaning "even so"] - see: https://www.wordreference.com/pten/entanto with the example
Pensei que seria fácil achar um emprego, no entanto, eu estava errado → I thought it would be easy to find a job; I was wrong, though.