QIf I have 4 cards on the field, how do I resolve this amulet's first activated ability?

AIf you have 4 cards on the field when you activate this amulet's ability, you may resolve it in the following ways:

1. Search for 2 or more Omen–Thief followers, summon 1, leave the rest in your deck, then shuffle.
2. Search for 1 Omen–Thief follower, summon it, then shuffle.
3. Fail to find or choose to fail to find an Omen–Thief follower in your deck.

QWhen I fuse multiple cards with this card's ability, can I select a combination of cards from my hand and EX area?

AYes. For example, you can fuse 2 cards by discarding 1 Loot card from your hand and burying a Loot card from your EX area.

QCan Fuse abilities only be played from hand?

AYes, that's correct.