same here, I use him because there is a lack of good alternatives (and because his art and lines are badass) and like I said I think he wouldnt be OP at 8 provisions either but what do I know
. but he does have some purpose. often times, my opponents will try to gain dominance and while I have leader and beast in my deck, sometimes I need dominance immediately and imlerith sits at 9-13 depending on consume and auberon on board PLUS I can just annihilate the opponents big unit if it's still bigger than him with wrath next turn (if I didnt already use it). not having dominance is pretty much GG for my list. you could also just play yghern and ozzy for more consistent value.
that being said, I usually just play casual mode with this deck and I dont think imlerith has a place in your deck if all you aim for is winning. I'm more enjoying the thematic aspect of this deck.
I kind of wish they would rework imlerith again and make him truly terrifying but I dont think it's going to happen.
and btw, naglfar is not bad imo, it's not an oneiromancy kind of card but just a consistency tool for r2 or r3 and imo has very good synergy with imlerith. it's just that imlerith is too costly I think.
edit: but what's funny about the WH archetype is how it relies on dominance but is HORRIBLE at keeping dominance. in any monster mirror I'm usually screwed because the 0815 consume decks can go way taller with ease. it's such a bad concept tbh, you desperetly need dominance which is literally impossible against decks like hidden cache, symbiosis, probably even SK with their new greatswords and endless removal, shieldwall etc etc. but at the same time you're not allowed to tech in tall removal like heatwave, igni etc because it breaks devotion. those two mechanics go sooo poorly together, it's actually really frustrating sometimes.