Duskshell Crawler

1, T: Add UR.

Flying When this creature enters, you may discard a card. If you do, investigate twice. T, Tap X untapped artifacts you control: Copy target instant or sorcery spell you control with mana value X. You may choose new targets for the copy.

Flying As this creature enters, you may return a nonland permanent you control to its owner's hand. If you do, this creature enters with a +1/+1 counter on it.

First strike (This creature deals combat damage before creatures without first strike.) Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

This creature can't be blocked by more than one creature. Each creature you control with a +1/+1 counter on it can't be blocked by more than one creature.

Menace (This creature can't be blocked except by two or more creatures.)

2U: Target creature can't be blocked this turn.

Spectacle 2B (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.) When this creature enters, it deals 1 damage to you and you draw a card.