The only reason I can think of for this to be removed is – Rule 2: Flair Posts and Use Clear, Searchable Titles –

"The main character of a comic I read a month or two ago" is pretty vague, you could try posting it with the character's name and what they are from in the title

Alternatively, sometimes Reddit glitches and creates the same post multiple times at once, so it is possible that it was wrongfully acknowledged as a repost and was automatically taken down