Knowledge Pool

Any other abilities that trigger when you cast the original spell (for example, if you cast Emrakul, the Aeons Torn) will still trigger and go on the stack.

Timing restrictions based on the card's type are ignored. For example, you can cast an exiled creature card this way. Other restrictions, such as Spinal Embrace's "Cast Spinal Embrace only during combat" are not ignored.

The spell a player casts from their hand won't resolve if it's exiled, even if that spell can't be countered by spells or abilities.

If the original spell isn't exiled (perhaps because it's countered by another spell or ability before Knowledge Pool's second triggered ability resolves), the rest of the ability does nothing. The player doesn't get to cast an exiled card.

You may cast any other card exiled by Knowledge Pool, including one owned by an opponent. Any card exiled by Knowledge Pool's "enters" ability or its other triggered ability may be cast.

If there are no nonland cards exiled by Knowledge Pool, the original spell is still exiled.

You may pay additional costs, such as kicker costs, of the exiled card.