[{quoted}](name=Düff McWhalen,realm=NA,application-id=3ErqAdtq,discussion-id=ao1LwATV,comment-id=00020000,timestamp=2019-11-16T18:06:10.197+0000)
I would consider it a buff if it made her flat out stronger. All extra tenacity would do is give her slightly more freedom in team fights. She'd suffer from exactly the same weaknesses she currently has over all.
Giving her extra stats does make her flat-out stronger. Not only that, but Tenacity is a broken stat. But giving a small amount of Tenacity tacked onto her passive, and only accumulating late-game is a small buff that would help her a lot, and be hardly noticed by her opponents.
Only two champions in the game have a native Tenacity stat.
Giving Shyv a significant Tenacity stat that is active in dragon state conflicts with the current design of the ability. Shyv R makes her unstoppable and is effectively a kind of cleanse. R timing is a skill expression (as much as it can be, since the Ult itself is kind of wonky). So giving her Tenacity after the Ult makes very little sense. (Don't engage with R. Let them sepnd all their CC, and THEN R.)
Shyvana wants Tenacity. She craves it. But making it active on R would seem silly. A Tenacity component to dragon stacks (basically a kind of Legend Tenacity stacking at half-speed) should be more acceptable.