Hi shadow! As people pointed out already, I can't proc soulburst off a dying serpent, but when it dies, I roll 12 dice. Usually at least one 1 is present, then it gets allocated to the warlock, and poof -he is dead just as I need him to
As for overwatch, Jain zar does the trick. All my banshee units always charge under her cover. Zone of her aura is sufficiently big, since all I need to do is to have 1 model slightly within range. In the rare cases where it's impossible for whatever reason (she's dead or a couple of squads acting independently on other side of the board), I only charge things that cannot hurt me much, or from behind the corner or simply eat up overwatch with wave serpents.
Teh metil: You guess absolutely correct. Due to overwatch not being applicable, I always declare everything within 12 a target of the charge so I can engage maximum.
As for the new faq - autarch is a monster in terms of effectiveness. He definitely stays. I don't really need Yvraine in this list - she walks in tandem with shooty infantry units which I dont use - I tend to proc off a dying enemy instead. Rather, in the light of flyers again losing the ability to score objectives, which kills one of their crucial functions, I'm gonna try to squeeze the Yncarne in instead, and probably a 4th serpent as well. Got a Sylvanas Windrunner Yncarne model being painted anyways More symbolism towards the blood elves.