Blue Sun's Twilight | Dockside Extortionist | Chandra, Hope's Beacon

(and two other cards)

Cast
Blue Sun's Twilight by paying ({5} magic symbol) ({U} magic symbol) ({U} magic symbol) , targeting
Shipwreck Dowser.
Chandra and
Displacer Kitten trigger.
Resolve the
Displacer Kitten trigger, blinking
Chandra.
Resolve the
Chandra trigger, creating a copy of
Blue Sun's Twilight, targeting
Dockside Extortionist.
Resolve the copy of
Blue Sun's Twilight, creating a token copy of
Dockside Extortionist.
The
Dockside Extortionist token enters the battlefield, creating at least eight Treasure tokens.
Resolve the original
Blue Sun's Twilight from step 1, creating a token copy of
Shipwreck Dowser.
The
Shipwreck Dowser token enters the battlefield, returning
Blue Sun's Twilight from your graveyard to your hand.
Activate seven Treasure tokens by tapping and sacrificing them, adding ({5} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Activate
Chandra's third loyalty ability by removing four loyalty counters from it, dealing four damage to up to two targets.
Repeat.
Once you have infinite mana, you may instead target
Shipwreck Dowser and any other creature to get infinite copies of any creature on the battlefield.

WARNING: Combo contains cards that are banned in Commander