Hello everyone.

Ive been playing ES since late 2016 and I just recently acquired omens of ice expansion.

I currently have: the core game + unseen forces, gates of arkham and omebs of ice.

My questions is. Can I use all ancient ones or other world cards from arkham city in the new expansion?

There are ancient ones that open up portals when adding doom tokens. I know several items, like the ones that give you a membership card are useless, but im not sure about the ancient ones or some other world cards.

Id really appreciate it if someone could give me some tips or insight about this

2 items are useless: Sheldon's Finest (common item) and Sigil of the Order (unique item) because of memberships. All the other items can be used.

Ancient Ones can be used in any mode: if you check the rules for Gates, it's stated that the gate icon is treated as an icon forcing you to lose 1 San when triggered

All OW cards can be used in any mode: restricted icons where used because cards were thought to be unplayable without Arkham, but in the end they are perfectly playable, so, no issues here

Hope this helps!