I use it all the time Lujo. it adds up to a 10 percent damage bonus in most cases, and is absolutely dynamite in dungeons with heaps of incidental items like spoons and pendants.
Also, try using it with wizard. Amazing.
The pacts aren't meant to synergies with anything really, just provide another way of eking out stats and strats from piety you might not use. You are looking for purpose in a mechanic that has little.