Simple solution, kill the cleric or are you saying that this is too difficult for 20 people?Also, I can most definitely argue skill. I've won a war 2 (me + ea) vs 20, without even being attacked while carrying the flag on one cap. So nice seeing 20 idiots chase the EA all over the map while running with the flag unhindered. 20 idiots < 1 person doing something right. Yea, it's difficult but if you KNOW that this particular duo is a dangerous carrier/support combo then why don't you prevent them from getting it. Oh, that's right, you're rpking untill they already have the flag and by then it's too late. Maybe you should consider taking them out before they can get the flag.
I've purged Feone several times of his purify buff and we've been able to kill him and he's way better than that veno Jolhan was talking about. No one was attacking that EP/Mystic combo healing the veno and no one bothered to try anything (someone said that because their armors are OP we, 20 people, couldnt beat 5 of them). More than half the people just stood afk in the centre doing nothing like a bunch of idiots. Purify isnt the problem in my opinion, stupidity is the problem.
As cleric with purify weap I can say... YOU'RE SO WRONG that we have advantage with it! Try play a cleric in just one single NW or TW and you will see how much you die. Even though purify procs, when you have 10+ people on you not even dear God can save you. Its all about teamwork and not about purify or IG or def lvl idk what else you mentioned there.