Karador, Ghost Chieftain | Slick Imitator | Narset's Reversal

(and one other card)

({2} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) plus enough mana to cast the extra turn spell each turn available.

Cast
Karn's Temporal Sundering by paying its mana cost.
Holding priority, cast
Narset's Reversal by paying ({U} magic symbol) ({U} magic symbol) , targeting
Karn's Temporal Sundering.
Holding priority, activate
Slick Imitator by paying ({1} magic symbol) and sacrificing it, copying
Narset's Reversal, with the copy targeting the original
Narset's Reversal.
Resolve the copy of
Narset's Reversal, copying the original
Narset's Reversal targeting
Karn's Temporal Sundering, and returning the original
Narset's Reversal to your hand.
Resolve
Karn's Temporal Sundering, causing you to take an extra turn after this one.
Cast
Slick Imitator from your graveyard by paying ({1} magic symbol) ({U} magic symbol) .
Repeat each turn.

If you've cast a creature spell using
Karador this turn, you may move to your extra turn, and then do step 6 followed by steps 1-5.