So like Rhino but with a belly? Sounds interesting to me!
That one foe in Fist of the North Star comes into mind (the one with the belly that takes a whole lotta punches to punch past that big belly).
The power set could be this:
Passive: Iron Stomach-
Impact damage is reduced by 70% for one hit, then 40% for the next, then 15%; then temporally fades for 5 seconds after (kinda like adaption for impact damage, but the more hits, the weaker it becomes)
1st Power: Grapple & Slam-
Pick up an enemy and slam them on the ground, making them lay still on the ground for an extended amount of time!
2nd Power: Cannon Ball Press-
An AoE cannon ball jump on the floor/enemies, with a interesting knockdown effect on them. Works great after using Grapple & Slam (doing so for increased damage on said enemies).
3rd Power: Steel Orb-
The "tummy" shoots out as a iron ball, dealing great Impact damage to those who dare enter his path.~
4th power: Rolling Strike (Exalted weapon)-
Like Atlas' stone wall's 2nd cast, rolls about, but you are the orb of doom, Tenno. Bowl down your enemies with a thunderous strike!~
...Ya, I'd totally play that frame!