I head that the sacrifice ability wasnt allowed to take place after the declare blockers step. Ex: I atk with Carrion Feeder, blocked by Thorn Elemental . Can i sacrifice 3 creatures to give Carrion Feeder +6 +6, after Thorn Elemental is assigned as a blocker?
Yes you can. After the blockers are declared, you are passed priority and are able to sac the creatures for your feeder.
RESOLVED
Sry, the card i ment was {Nantuko Husk} . But the point was a buddy told me the rules had changed i was just checking.
What about when I block I have a card that says forest sacrifice search you library for a land after I block can I still do its ability
Yes. Activated abilities of creatures work at instant speed ( as long as they don't have summoning sickness) and can be activated after it blocks.