This is for those who likes to clear every single cave/dungeon with tyreal. If you simply get 5 nephalem stacks and kill siegebreaker and reset, this is useless.
I am currently playing on a rather unstable connection, and i often DC and lose my nephalem stack, before i got to the siegebreaker assault beast. This sucks alot if you are doing long farming sessions, clearing ice caves, other dungeons etc. with tyreal and letting him kill any hard pack, and finishing with killing the siegebreaker assault beast.
However i found a way to go right for siegebreaker when you get to 5 stacks, kill him for the massive ammount of loot he drops, then continue farming the rest of the elite packs/chests in dungeons / caves and such.
You simply pull the assault beast, get him to kile 0-5 % hp, and let him kill you. You will now wait a few seconds while tyreal does the killing for you. And unlike when you kill him yourself, adria does not spawn. You are now free to teleport back to town. And continue farming the other area's if you like so, without worrying about a disconnect ruining the loot pinata feast on siegebreaker.
Note, its not possible to enter the arreat crater with him, as this causes him to despawn and skip to the next quest.
I hope this is useful for some people who "enjoy" farming all the area's for loot.