Having a bear by your side when you duel does multiple things for you. First of all, when you teleport there is what we call the minion stack bug - which means if something like say FOH lands on you, it will hit your minions first - which means your bear with good life will take the hits first. Also, lets say there is somebody attacking you with melee... The bear can take some hits for you, so you lose less life. Besides... you can just recast the bear. The same principle works with going against monsters as well.