Tetsuo, Imperial Champion | Savage Beating | Call to Mind

(and two other cards)

Savage Beating in hand.
Tetsuo and
Invasion of Arcavios // Invocation of the Founders on the battlefield (
Invasion of Arcavios // Invocation of the Founders as Invocation of the Founders).
Call to Mind and
Mystic Retrieval in hand or in your graveyard.

Tetsuo has an Equipment attached to it with mana value 5 or greater.
Tetsuo does not have summoning sickness and cannot be blocked and killed by an opponent.
One of
Call to Mind or
Mystic Retrieval must be in your hand, with the other in your graveyard.

Declare
Tetsuo as an attacker.
Tetsuo triggers, causing you to cast
Savage Beating without paying its mana cost, choosing its second mode.
Invocation of the Founders triggers, copying
Savage Beating.
Resolve both
Savage Beatings, causing you to get two additional combat phases after this one.
Move to your first combat phase.
Declare
Tetsuo as an attacker.
Tetsuo triggers, causing you to cast
Call to Mind without paying its mana cost, targeting
Mystic Retrieval.
Invocation of the Founders triggers, copying
Call to Mind, targeting
Savage Beating.
Resolve both
Call to Minds, causing you to return
Mystic Retrieval and
Savage Beating from your graveyard to your hand.
Move to your second combat phase.
Repeat steps 1 through 4 one additional time.
Declare
Tetsuo as an attacker.
Tetsuo triggers, causing you to cast
Mystic Retrieval without paying its mana cost, targeting
Call to Mind.
Invocation of the Founders triggers, copying
Mystic Retrieval, targeting
Savage Beating.
Resolve both
Mystic Retrievals, causing you to return
Call to Mind and
Savage Beating from your graveyard to your hand.
Move to your second combat phase, and repeat from step 1.