Nardole by tapping it, adding at least six ({U} magic symbol) that can only be spent to cast noncreature spells.
Cast
Whispers of the Muse with buyback by paying ({5} magic symbol) ({U} magic symbol) .
Chakram Retriever triggers, untapping
Nardole.
Resolve
Whispers of the Muse, causing you to draw a card and return
Whispers of the Muse to your hand.
Repeat.
If
Nardole has at least seven counters on it, this combo nets near-infinite ({U} magic symbol) that can only be spent to cast noncreature spells, and you may target any other creature using
Chakram Retriever's trigger.
Results
Infinite card draw.
Infinite draw triggers.
Near-infinite blue mana that can only be spent to cast noncreature spells.
Near-infinite magecraft triggers.
Near-infinite mana creatures you control can produce.