User blog comment:Emptylord/Custom Champion - Nighthawk the Winged Fury (2013)/@comment-62.249.103.45-20130101212646/@comment-3974211-20130102085121

It is calculated per strike.

If Nighthawk is as 50% health when he uses the skill, the first tick will be 3% * 1.5 = 4.5% of their maximum health. This will heal Nighthawk, and so the next tick may only deal 4%, then 3.5%, etc (it is unlikely that Nighthawk would heal this quickly, but just as a comparison).

Let's assume best case scenario - Nighthawk is somehow taking damage at the same rate he's dealing damage (and so his health remains at 1% for the entire duration). The maximum damage of this skill is 30% x 1.99 = 59.7% of their maximum health.

Yeah, the ultimate is similar to, but I really wanted a vampire-feasting-on-your-neck skill... which, unfortunately, is themeatically similar to a werewolf suppressing you. So I just did my best to make it feel different - Nighthawk doesn't suppress you, you can still move around (and potentially drag him under tower).

I could lower the base-total damage, but I was honestly stumped about how to balance the damage of his ultimate.
 * In my opinion, Warwick's ultimate *feels* super-weak at all stages of the game unless you build on-hit or excessive amounts of damage - which a lot of Warwick's don't do. It's almost exclusively used as a CC skill. So I knew I would probably need percentile damage.
 * Evelynn's ultimate does 15 / 20 / 25 % of maximum health to all targets instantly. 20 / 25 / 30 % over 3 seconds to a single target seemed fine.