Ermor Themes

[regret]

Hi all,

New to game but got a question to ask

i am trying Ermor themes at the moment
Can someone explain to me what the difference is between the different reanimates and call spirits options?
like which uses population or corpses or no requirement?
and roughly what i will get using the different options?
i roughly know that dominion effects and unholy rating of the summoner is how much you get
and that longdead doesn't require anything
and of course the 2 tips they show saying reanimate souless needs corpses and ghouls need pop.

thanks in advance