Clever Impersonator | Estrid's Invocation | Oblivion Ring

(and one other card)

Clever Impersonator and
Estrid's Invocation in hand.
Oblivion Ring and
Sage of Mysteries on the battlefield.
({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) available.

Cast
Estrid's Invocation by paying ({2} magic symbol) ({U} magic symbol) .
Estrid's Invocation enters the battlefield, triggering
Sage of Mysteries and itself.
Resolve the Altar of Brood trigger, causing each opponent to mill a card.
Resolve the
Estrid's Invocation's trigger, becoming a copy of
Oblivion Ring and exiling
Oblivion Ring.
Cast
Clever Impersonator by paying ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Clever Impersonator enters the battlefield, triggering
Sage of Mysteries and itself.
Resolve the Altar of Brood trigger, causing each opponent to mill a card.
Resolve the
Clever Impersonator's trigger, becoming a copy of
Estrid's Invocation and exiling
Estrid's Invocation.
Estrid's Invocation leaves the battlefield, returning
Oblivion Ring from exile to the battlefield.
Sage of Mysteries and
Oblivion Ring triggers.
Resolve the Altar of Brood trigger, causing each opponent to mill a card.
Resolve the
Oblivion Ring's trigger, exiling
Clever Impersonator.
Clever Impersonator leaves the battlefield, returning
Estrid's Invocation from exile to the battlefield.
Repeat from step 2.