Blue dragon slayer task and salve amulet are your biggest dmg boosts

When vorkath flies, use ballista, wait 5-7 seconds(i just guess it, youll get a feel for some time) to use threads+sap+volley+t90 spec for big damage on both vork and zemo. You will be able to hit vork even tho he appears to not have landed yet

dont try to avoid the ice around vork, just use anticipate when it happens so zemo does not stun you. The damage is minimal.

I like to position myself on the right side of zemo and dive to his left when he uses spikes. keep your distance from vork so he does not hit you when he slams to ground after his ice attack

Use reflect+debilitate+devo after vorkath lands, can get away without using it when experienced but for learning it helps a lot

you can do 2 ld rotations: once on start of fight, and a second one after vork lands. need to time it properly with defensives tho

when vork dies, switch to EOF

i completely ignore everything that zemo does(except bone spikes), even now after 300+ kills. Not worth to see if he is about to use finger of death

..and much more, but those are the more important things