If you get in his way...... he kills you...... and if you are weaker than him ...... you will get in the way.......ergo you are dead........ killed by Sesshomaru......
What I mean is that if you want to fight alongside him you need to be insanely strong...... enough to compare with him at least...... if you cant do that much then he has no need for you...... unless he needs a replacement for Jaken......
His policy is quite simple.... when he fights ..... he wants no interference...... and if you are weak..... you count as interference......
(Not seen anyone in the anime or manga who can challenge/compare to Sesshomaru one on one without any tricks.....not with Sesshomarus current level of power..... which is only going to increase)
