Yeah! Eustace is a great guy, right? He's not big on saying 'friend', but he's reliable to work with too on quests.

[Be good friends with him, k, Izuku??]

No one has said you shouldn't. I mean, I guess they said your familiar is supposed to look out for you well-being, it'd make sense not to spar with them, but it's a few bumps and bruises, and hey, it gives people with Healing magic something to work on.