Oh God. Jeremy Renner cannot sing. Well, he's better than Pierce Brosnan in Mamma Mia!, but that's not saying much.
The gag here is supposed to be 'LOL look at Hawkeye sing an Ed Sheeran song about all his "other" super powers that we don't know about because Hawkeye is a crap superhero' etc., but all it turns to be is another example of actors who should never, ever, ever cross over into singing.
This is painful. And it's all Jimmy Fallon's fault.