New-Toushirou would honestly be kind of impressed with his former self in some ways. So . . . a captain of death gods (that . . . apparently protect souls instead of devouring them or whatever, so that makes being a death god okay), with a whole whack of useful powers and people that actually listen to him. He can get behind that.

On the other hand, New-Toushirou would be rather unimpressed with the fact that Old-Toushirou didn't see what kind of danger was around his own best friend for years and years and start criticizing him for his screw-ups in protecting her. Because being critical solves everything.

Old-Toushirou doesn't really know how to deal with kids, but if this is really him, then it shouldn't be that hard, right? Don't have to treat him as much like a kid. Except shutting him down when the kid is being a brat and getting on his case about how he wasn't able to protect Hinamori. Shut up, child. They alternate butting heads and getting along fine, because that's how people like them roll.

As a side note, Old-Toushirou is quietly unhappy that his new self gets to be taller. And New-Toushirou starts mentally griping that future echoes may make him shrink. Not. Fair.