Each opponent loses X life and exiles the top X cards of his or her library, where X is the number of instant and sorcery cards in your graveyard and that you own in exile. You may cast cards exiled with Arcane Drain until the end of your next turn.
Dahammer4
Artifact - Equipment (R)
Choose one - Equipped creature gets +4/+0; or Double Strike; or "When this creature deals combat damage to a creature, exile that creature"; or t, unattach ~ from this creature: ~ deals 5 damage to target creature." t: Equipped creature gains flying until end of turn.
Equip 3
Mana Cost: 5UB
Instant
Each opponent loses X life and exiles the top X cards of his or her library, where X is the number of instant and sorcery cards in your graveyard and that you own in exile. You may cast cards exiled with Arcane Drain until the end of your next turn.
Sigpic by Rivenor
Artifact - Equipment (R)
Choose one - Equipped creature gets +4/+0; or Double Strike; or "When this creature deals combat damage to a creature, exile that creature"; or t, unattach ~ from this creature: ~ deals 5 damage to target creature."
t: Equipped creature gains flying until end of turn.
Equip 3
Courtesy of Crepes
[OMC] Omerium's Collapse
It's really because of flashback and other similar spell mechanics. This is meant to be a "reward" of sorts for spellslinging.