Cast a copy of Maestro's Gift by paying {3}{U}{R}, targeting Inspired Skypainter.
Maestro's Gift's storm ability triggers, copying it for each spell cast before it this turn. Choose to have each copy target Prismari.
Resolve the first copy of Maestro's Gift targeting Prismari, creating a token copy of Prismari with haste.
Repeat step 3 for each remaining copy of Maestro's Gift that targets Prismari.
Resolve the final copy of Maestro's Gift, creating a token copy of Inspiried Skypainter with haste. It'll enter prepared due to its static effect.
Cast a copy of Maestro's Gift by paying {3}{U}{R}, targeting Inspired Skypainter.
Maestro's Gift will have a storm ability for each Prismari you control, and each storm ability will trigger.
Resolve the first storm trigger, copying Maestro's Gift for each spell cast before it this turn. Choose to have each copy target Prismari.
Repeat step 3 for each copy created in step 8.
Repeat steps 8 and 9 for each remaining storm trigger from step 7.
Repeat from step 5 as mana allows.

Near-infinite ETB

Near-infinite creature tokens with haste

Prismari, the Inspiration

Inspired Skypainter // Maestro's Gift

Sakashima of a Thousand Faces

Cast a copy of Maestro's Gift from exile by paying {3}{U}{R}.
When you cast that spell, Molten-Core Maestro triggers, putting a +1/+1 counter on itself and adding an amount of {R} equal to its power.
Maestro's Gift resolves, creating a copy of Inspired Skypainter who enters prepared and with haste.
If needed, activate Energy Refractor by paying {R}{R}, adding {U}
Repeat, adding an ever-increasing amount of {R} in step 2.

Infinite +1/+1 counters on a creature

Infinite ETB

Infinite colored mana

Infinite copies of a specific creature with haste

Infinite magecraft triggers

Infinite storm count

Molten-Core Maestro

Energy Refractor

Cast Maestro's Gift from exile by paying {U}{R}, creating a token copy of Inspired Skypainter with haste that enters prepared.
When the token enters, Mana Echoes triggers, adding {C} for each Lizard or Wizard creature you control.
If needed, activate Gemstone Array by paying {2}, adding {U/R}.
If needed, repeat step 3 an additional time.
Repeat.

Infinite charge counters on a permanent

Infinite colorless mana

Infinite creature tokens with haste

Mana Echoes

Gemstone Array

Cast a copy of the prepared spell by paying its mana cost.
When you cast that spell, Displacer Kitten and Dovescape trigger.
Resolve the Dovescape trigger, countering the prepared spell and creating a number of 1/1 flying Bird creature tokens equal to its mana value.
Resolve the Displacer Kitten trigger, blinking Inspired Skypainter // Maestro's Gift, which enters prepared.
Activate Phyrexian Altar by sacrificing a Bird token, adding one mana of any color.
Repeat step 5 until you have enough mana to cast the prepared spell.
Repeat.

Combos with "Inspired Skypainter // Maestro's Gift"