by all means, please go tank 10 seyren with safety wall and live to tell the tale. i got respect for you shuck, but dont forget to post the replay vid of this ultra fail idea. we're talking about party efficiency, not the abilities of what one skilled player can do with their character.
keyword here, "most" ti's. tell me how your rangers are going to camo against seyren when they're demon. tell me how, when there are other parties on the map killing stuff that, seconds later, spawns on your party and attacks your party members at random, do you expect your party to live without a tank? at least in that situation a sura can CC everything while people regroup (quickly).
apparently you're either very new and dont have much experience against seyren, or you seriously overestimate the abilities of new players lol.
I think you're forgetting how much damage Arrow Storm and Dragon Breath deal. Most monsters don't even have time to respond,the poor things.