What to do with it? It has no +% damage, only via a modifier on mogdrogen’s pact. It has big health and a hefty amount of flat damage, so I you’d want a shield skill.
First that came to mind is of course Aegis. My attempt as a bit meh, but there’s this old build which probably performs better.
I was fiddling around and somehow landed on vit foi: Vindicator, Level 100 (GD 1.2.1.6) - Grim Dawn Build Calculator
It doesn’t look amazing, but maybe it works? However it’s not a shield skill (I doubt it’ll take the off-hand damage for the %WD on foi)
(As an aide I checked if maybe Seal of Blight uses the shield if I put it on my shield. It doesn’t, only if don’t equip a weapon in the other hand apparently. 
)
Other shield skills that I know about:
Vire’s Might
Blitz
Forcewave
I heard vire isn’t great as a main skill. Not sure how you make the other two work with vit 
Has anyone made a working build with the meatshield?