Tham kench and %hp dmg
can we discuss for a second on how absurd tham kench is? a tank with %hp dmg (shen too, lets not disregard that) is insane, any tank with %hp damage should either 1 be removed from the damn game or just remove it, it's really not that hard to fix. bit noooooooooooooo riot doesn't want to fix it because it's "balanced" alright so put kench in top lane. 1, he shreads tanks like no tomorrow, 2, he's a tank himself, and 3. if you don't have a vayne on your team, he dominates. that's straight absurd and everyone knows it, cmon riot, just fix it ffs.
In short, percent health is a mere means for tanks to do notable damage without having to worry about building anything outside of tank items/runes. Tahm is just among the worst, mostly because of his Munch-Munch Fruit mechanic.