User blog comment:Willbachbakal/(CB1) Hannibal, the Dread Vanguard/@comment-24385282-20150326024802/@comment-7709681-20150326035332

Fills up to 40% of his max. health, not 60%, and even then the damage scales as 16 / 24 / 32 / 40%, he does not deal the max. damage from the beginning (It used to, but meh :V).

At it's best, reaching 4K - 5K health deals 1.6K - 2K damage, but would be really hard to do so, and even then the ability, as Will itself mentioned, is supremely telegraphable, easy to read and avoid.