Ok here we are
multitankin :
so i will state some ways of multitankin : thunder clap improved in talents helps a lot in multitankin it does so because = once warrior makes pull first of all make bloodrage so u get the 50 threat bonus (improved for sure) than once mobs come spam thunder clap on them , once u thunder clap them u make AOE damage + slow effects which help the mobs not to attack mages etc .. each thunder clap it adds a stack up threat on each mob that makes it easier to aoe tank them plus if u are a fast player u can swap players while tankin and put 1-2 sunders on each mob u tank , Demorilizing shout helps to take less damage from all mobs so Yes always use it so u can last longer , and once all mobs are on u if one goes away either from AOE of mage or hunter just Taunt it fast or Aoe Taunt is used for emergency mostly helps to gain aggro too / .
*Note : Paladins help a lot for AOE tankin bcz they can Reset aggro so u can thunder clap and gain all mobs again on u
Once AOE tankin in progress it is best to nuke mob by mob as aggro controll will be eaiser too but dont forget that healer makes too much aggro too so usualy u need to make the fastest DPS on mobs so they can die fast bcz multitankin doesnt last for long