If Unstable Amulet leaves the battlefield before you play the most recently exiled card, you can play that card for as long as it remains exiled
Kessig Forgemaster / Flameheart Werewolf Likely filling out the 2-mana slot for a werewolf typal deck, Kessig Forgemaster / Flameheart Werewolf can be annoying to block
It becomes a legendary Spider Hero in addition to its other types
Previously, in cases where a cards mana value differed from the resulting spell, such as with some modal double-faced cards or cards with an Adventure, you could cast a spell with a higher mana value than the exiled card
I myself, never really used the Factorys ability to boost other Assembly Workers, unless I didnt have the Mana to attack with two of them separately
Reprints of the card are inexpensive, but Alpha copies are costly