Hey there, I was just like you, annoyed about the unkillable venompool.
I tried different champs , I used over 7 energy refills UNTILL I finally found the counter.
I used a r4 5* Sabertooth with Killmonger synergy.
Far right lane if you fight adaptoid with Sabertooth then when near opponent you inflict a Stacking Poison , Each poison refreshes the cooldown of the previous ones added. End fight with sp3
You now have 7 furies. Fight VtD with anyone else.
Use Sabertooth vs Beast
You now have 14 furies.
Use your other team members to finish off the lane (in my case I used R3 6* bwdo , r3 6* nebula and r2 Winter soldier (alrdy got KM for Sabertooth).
Now you are at boss.
You use sabertooth. You stay near VP as much as possible. Stacking the poisons ( each reduces healing by 30%)
Try to extend the time on your hits.
M...L...L...L...M instead of MLLLM. Bait sp1 and fast go in again to not let poison fall off.
I had a timing error and lost all my poisons but within 10 seconds I rebuild the poison and started out damaging him again.
I ended on 28 poisons (3k ish per tick and no healing) and around 16 furies.
P.S I duped my r3 nebula for second time as reward
