You can counter a lot of high damage ult or abilities with obliterate or your ult. Maxing out at 80% damage reduction if done correctly with cards and timing.

Vora does not counter Zhin for he has high damage plus sustain. He can time your obliterate w/billow&dash to counter it or cleanse bleed w/billow. To fight him: build stacks then fight. If not max stacks keep outside his basics

Your basics don’t feed into his reversal. But your DS WILL

Her inferno cannon lasts too long to negate with your obliterate even if you wait it out by burning your hp. Simply use your obliterate to avoid the root and then use tendrill to avoid her inferno cannon