I'm really in to necro-stuff, but real games showed me some downsides of playing necromancy-oriented deck. The question I have here - is it rational to use suck combo:

I have Countess Iseara and Crypt Ghouls . If I pay 1 resource token, I grant CG necromancy ability, when they are in d/p (I think about Slave Pen sacrifice or Northern Wastes , or any other way you can offer). And from this moment an infinite loop can begin. If I use necro ability and play them for their 2 r/t, then sacrifice, can I summon them again?

Cause if there is such option, then Offering of Blood becomes a card of a great value. If I'll necroplay CG into the zone with Warpstone, then I'll be able to give Great Unclean One just infinite power. Daemon Prince will attack as soon as this loop will be launched.

So, for the god's sake, tell me, is this loop possible or not?

P.S. I understand, that Countess is an expensive card to play, but it's quite possible to use her on the early phase.

Necromancy lasts when card is in discard, comes backs into play, goes to the discard again and game no longer "remembers" that this card had necromancy.

as said in rulesheet, "you can play this card from discard pile. if it survives until the end of the turn, put it on bottom of your deck". I assume, that if the card is destroyed/sacrificed it has to be put into d/p. then constant effect (necromancy) is on. or I am not correct? where I can find more detailed necromancy mechanics?

Update

Found CI topic, with out of play explanation. okay then, if I pay 1 r/t each time I want to play crypt Ghouls will the GUO receive hammer for sacrifice?

If unit has necromancy keyword printed on it you can play it from discard as many times as you want. If you give necromancy to an unit by Countess ability that unit will have it unless it goes to discard again.

I've already got it. What about my update question?

Found CI topic, with out of play explanation. okay then, if I pay 1 r/t each time I want to play crypt Ghouls will the GUO receive hammer for sacrifice?

Yes.

Nice. So there comes an ultimate question – is there a reason to use this combo, or better find other options for painless sacrifice?

This combo is expensive, requires two 6 cost units, warpstone as restriction and ghouls = 4 cards.