We really don't have ANYONE who embodies the power of Mjolnir, no hammer toting Norse badass.

So why not rework Taric into a.. son of Odin, Mjolnir wielding-esque beast? He could still have an affinity for gems, they could've been bestowed upon him after being recognized by some sky god for his deeds, or having came from the earth, they represent that essence, hammer in hand, gems embedded in armor, sky/ground.

Olaf is a lost cause..

I don't know man, I say rework Taric but his identity as a Paladin would be lost, and this Valhalla junkie would be restricted to support? meh. They either need to come out with a new champion like this all together, or rework Taric and then come out with a more realistic paladin later on.