They way I'm going to solve this riddle, is to ask myself what skill the jerk-offs at GPG could have given the already miserably overpowered UB to make him even more dominant.
Let's take away Foul Grasp, an already awesome skill, and see if he's better off with any of the other 5-10-15 skills
Boulder Roll? Better maybe since he can level it up... but kinda nice that FG is awesome with only one skill point, boulder you need more to make it deadly.
Batswarm? He's already really really really tough to kill, but has natural speed and snares to go with it, might be better...
Silence? YES! Beast and two of the worst demigods beat any other team if played by players of equal skill.
QoT's Spike Wave replaced by Silence? She is now Tier 1.
Pretty much anyone I can think of, if you replace their best 5-10-15 point skill with silence, they are better... except for Sedna, she'd be just about the same.
A five point skill line? Hmmm... not sure.