Nobody. Why would a normal person kill companions except in the most extreme situations?
That said, Lae'zel died when she and Shadowheart decided to fight it out. My main sided with Shadowheart because a) she doesn't like Gith, b) she didn't like Lae'zel, c) she wanted to sleep with Shadowheart (plan failed after she got busy first with Gale) and d) she was unsure what would happen to the articact if Lae'zel got it. Poor Lae'zel.
Second dead was Halsin. He was too massive and muscular to get back through the Shadow Portal, some less fitness training and anabolica abuse would have benefited him more, so not my fault (ok, I failed to protect the portal ...).
