I havent found cloves to be that powerful in the meads ive made but cinnamon and nutmeg are overpowering even in small amounts. ginger is nice I would use dried root not the powdered stuff or the fresh root, star anise is nice but only in small amounts i wouldnt use more than one pod in a 3 gallon batch. a little orange peel could work, apple juice for a cyser works well with spices too. there are too many spice to list that would work in that mead but to name a few, juniper, corriander, fennel seed, paradise seed, licorice root and a million others.
clover honey is nice for mead but it is a very mild honey, using small amounts of other honeys like you would specialty grains in beer can add a really nice flavor. depending on the honey and pomegranate juice you use you may want to add acid to it but most people do that at bottling and just and acid blend to taste. also carbonation with completely change the way the spices come across, sparkling spiced meads seem stronger than still ones, and certain spices combined with carbonation can really burn the back of your nose when you drink it.