Tulio is definitely one of Envy's Really Important People! And more than that, he's a friend and someone who Envy feels like he can really trust. He's much more willing to open up to Tulio than he was before, and he's okay with Tulio seeing him when he's in a weak/vulnerable state (like when he was sick or after Nanao left). Another thing that happened when Nanao left was that Envy became really concerned about Tulio disappearing, so he likes to know where he is and doesn't wander off on his own quite so much anymore (and if he does, he lets Tulio know where he's going because Tulio was really clearly worried about the same thing). He just really, really doesn't want Tulio to leave ever.

The fact that Tulio is a human is still something Envy does still notice, but it's mostly a background thing by now and Envy doesn't mind it at all anymore although it does make him worry sometimes HUMANS ARE FRAGILE OKAY. He's always up for teasing and arguing and bantering with him, just as he always has been, and Tulio can get away with pretty much anything, including things that would have been very dangerous with canon!Envy. Envy doesn't want to hurt him, so Tulio would be safe even if Envy got incredibly angry. He does worry about Tulio getting caught in any castmate crossfire though, since he's got enemies showing up.

He also doesn't think Tulio is using him anymore! Which is a very good thing because that was a strong assumption for a while even after it wasn't true anymore. Since he's not used to having a 'group leader' sort of person that isn't using him, it's strange for him but he feels more comfortable and secure in the group.

tl;dr HOORAY FRANDS