Interesting, because Castlevania is a Japanese IP, but is written by Warren Ellis and animated by the same studio as Adventure Time, one of the most beloved series to come out of the 2010s animation boom. Meanwhile DotA: DB is a western IP that was animated by Korean Studio Mir (who have also worked on the final seasons of both Legend of Korra and the Boondocks in the past).
I got more "anime" feelings from DOTA than I did Castlevania, but I also consume more fantasy anime than the average person I think.
You know what, when you mention the movement of the characters, I see what you mean. Castlevania characters move more realistically, but it's still pretty stylized, thus the "almost anime" feeling.