Main Character
Asta by far to me. As others have stated, Deku is too whiny and annoying. Asta is a pretty stereotypical shonen MC but I think that works best considering how the story is laid out.
Other Characters
MHA has higher peaks in how Endeavor is imo the best character out of both series. But Black Clover's cast runs deeper. Yami can definitely contend with Endeavor and Julius, Mereoleona, Fuegoleon, Zora, Charmy, Charlotte, Vanessa, Luck, and Finral are all solid and good characters. Concerning the main three for each series, Black Clover definitely wins. Noelle is far better than Ochako imo. Her development is great to watch and you always want to root for her to reach that next step. I already explained why Asta > Deku. Bakugo >> Yuno for me tho. I personally don't like Yuno at all but he doesn't drag Black Clover's character level down though.
Story
Black Clover easily. I stopped reading MHA months ago after pretty much just getting bored with the plot. Black Clover on the other hand always keeps me interested in what's happening next with each chapter.
World
Black Clover yet again. The powers are more interesting and creative. Quirks to me are too simple and stale. A few are cool but most are boring. Magic on the other hand can't get like that because there's almost no cap on how deep you can reach with it. Then you got the elves, the other kingdoms, etc. MHA just gets outclassed here.
Villains/Antagonists
This is the only category that I'd give to MHA. I don't like the Black Clover villains. The Dark Triad to me are meh and are just more of a big bad wolf type of villains. The Eye of the Midnight Sun are a little better but I personally didn't like either of them. Imo, Black Clover is great because of the plot and the side characters. Its villains are subpar. MHA on the contrary has some solid villains. Chisaki is great, I think Shigaraki is pretty cool and Dabi is one of my favorite characters. AFO was also dope as hell to me as we saw him. The rest are pretty meh but personally, those four are better than what Black Clover has to offer.