Sharm won't die until -72 HP. Any healing applied to a character at negatives brings him up to zero for free first - so a sharm 1 HP away from death (-71 HP) could end up at ~58 HP with a Healing Word from Brudd (leaving two more just for this encounter), gaining more than 100 HP in a one minor action.
Oh, and most of the enemies going between now and Brudd's turn are dead, so it's not like there will be enough attacks to kill Sharm before he can get healed.
And all of this damage is apparently 7, since this is the first time he's ever been in the area of one of her spells. You're taking a bunch of damage because, A) that's what happens - there's a reason healing is quick and easy, B) Sharm's AC sucks since you opted not to take the standard masterwork bonus for characters of this level, B) his Ref and Will also suck since his top two stats are STR and CON - which is a problem for fighter's of his style. So he's easy prey for the Cambions and the Ice Devil's Chilling Command thing.
Oh, and Senara is packing the ability to cast 3 ressurections.