Rek'Sai's Passive is pretty weak
Fury of Xer'Sai INNATE: Rek'Sai generates 25 Fury upon dealing damage with basic attacks, Unburrow, or Furious Bite, and loses 20 Fury per second if she hasn't generated any in the last 5 seconds.
While BURROWED, Rek'Sai consumes her current Fury over 3 seconds, healing up to 20-190 (based on level) health at 100 Fury, stopping once she consumes it all or returns to full health.
Are you serious? 190 health at level 18? And no scaling at all????? It isn't some "per Fury consumed" figure either. 100 Fury is UP TO 190 health!!
This is probably one of the worst passives in the game to be completely honest.
There are so many ways that this could be improved, even by a little.
Give it a small AD scaling, like +10% AD .. or even +10% BONUS AD.
Or give it a missing health scaling. Have the heal increase by 1% per 1% missing health. Hell, at 90% missing health that is still only a 360 hp heal. ... less actually since restoring health would decrease the overall % missing health ,... but not by much.
I would really like to see something stronger than these, but this would at least be something.