Tips on eman t3

I saw some videos for enderman slayer tier 3 and copied my gear exactly off of them. Voidedge, full final destination (16k+ kills each), 432MP, Wand of atonement, florid zombie sword, necromancer sword with tank zombies, and a mana flux orb.

The first guy I watched does double my damage per hit and has 200 more HP and defense than me. He has around 300MP.

The second guy deals triple to quadruple my damage and has 1000 more HP and also some more defense than me. He has around 450 MP.

These guys clear the boss with ease. On the other hand, I'm able to get through the hit phase but get melted in 5 seconds right after.

What could be the problem? Please don't say things like "increase your MP" ,"skill issue" or "get better gear". I have enough soul flow, I'm using my wand, I'm using my summons, I'm using my mana flow, and I'm using ny final destination armor's abilitie by sneaking. I'm not asking how I can improve my current gear and MP, i just want to know what the difference between these guys and me could be.

My skycrypt: https://sky.shiiyu.moe/stats/StephKorean/Kiwi

The guy who does twice my damage and has 200 more HP and defense than me: https://www.youtube.com/watch?v=ZgdcKK9R9I0&t=383s&ab_channel=FlameGameGod

The guy who does triple - quadruple damage and has almost 1000 more HP than me: https://www.youtube.com/watch?v=nIJfmEu73Jk&t=553s&ab_channel=ModernSoldier