Supremacy is not propagating Ultimate.

At this point, this is likely working as "intended," but if so the intent needs to change: Mastermind Henchmen aren't being buffed by the summoner's Ultimate.

This makes sense for normal pets, but for the Henchmen to not get level shifted is like having a Tanker whose attacks go up a level but whose shields don't provide any increased protection. Actually yeah, it's quite exactly like that.

And since Tanker shields DO benefit from Ultimate, so should Mastermind Henchmen. (-: