About puppets.
In .33 (don't know about .34- havn't played much CIV lately), you could use Hemah with death III to summon a puppet, move it into position, turn it into a lich, have that puppet-lich summon a puppet, turn it into a lich, have that puppet-lich summon a puppet, etc.... Then all the lich attack. Thats a pretty powerful force to unleah in one turn.
Also next turn you can summon many many puppets and use those to summon wraiths or more liches.
I have never gotten twincast with hemmah though so i can't comment on that.
Yeah, you could conquer the whole continent the turn any balseraph arcane unit got Death III. Throw in Water II and it was the entire world.
I haven't tested if they fixed it in this version.