When you kill a desperate merc you get a healing flip. Take the wound on nekima first, then heal it up as you kill the mercenaries.
My 35ss grow list (that cannot be taken to adepticon unfortunately) is
Lilith - 7 stone cashe
4 tots
3 mercs
nekima
Activate Nekima, use the power to get a blood stone. use the power that lets you add masks to your casting.
Activate lilith, kill merc, get a stone, nekima gets a stone, healing flip on nekima.
Activate tot, grow off lilith, mature off nekima, kill merc, healing flip on nekima, get a stone, nekima gets a stone.
Activate tot, grow, kill merc, healing flip if necessary, get stone, nekima gets stone, mature off nekimas 2 stones.
activate tot, grow off matures stone.
end result on turn 1:
Lilith
Nekima
2 mature nephilim
1 young nephilim
1 tot
I've also been meaning to post asking, is there any reason this isn't valid?