({3} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) available if Naru Meha is in your hand, or ({3} magic symbol) ({C} magic symbol) ({U} magic symbol) otherwise available.
Holding priority, if Naru Meha is in your hand, cast it by paying ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) .
If Naru Meha is on the battlefield, activate Eldrazi Displacer by paying ({2} magic symbol) ({C} magic symbol) , blinking Naru Meha.
When Naru Meha enters the battlefield, it triggers, copying Vantress Visions, with the copy targeting Karn's ability.
Resolve the copy of Karn's ability, adding ({C} magic symbol) for each artifact you control.
Repeat from step 4.
If you control four or more artifacts, this combo nets infinite colorless mana, which can be used to copy Vantress Visions infinitely targeting any other abilities on the stack, or to blink any number of creatures infinitely.
Results
Infinite blinking.
Infinite colorless mana.
Infinite copies of abilities you control on the stack.
Infinite ETB.
Infinite LTB.
Infinite magecraft triggers.
Infinite blinking of creatures you control except Eldrazi Displacer.