I know all of jack shit about summoner math, but I went out to test Fervor Ring today and it looks like Avatars have a base MAB of 44. I had heard 20 MAB thrown around in the past, but that seems to be incorrect.
This means that, with very basic MAB gear (no augments), level 90 Nirvana is a ~20% damage boost to magical blood pacts. Not exactly the godslayer people make it out to be, in my opinion. That's less than a level 51 staff bonus of damage increase.
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