Nonland permanents you control can produce at least ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) ({U} magic symbol) after being tapped twice.
Mana Needed
({R} magic symbol) ({G} magic symbol) ({W} magic symbol) ({U} magic symbol) at most available.
Steps
At the beginning of your end step,
Unstoppable Plan triggers.
Holding priority, activate all mana-producing nonland permanents you control by tapping them, adding an amount of mana.
Activate
Mister Fantastic by paying ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) ({U} magic symbol) and tapping it, copying
Unstoppable Plan's trigger twice.
Resolve the first copy of
Unstoppable Plan's trigger, untapping all nonland permanents you control.
Holding priority, activate all mana-producing nonland permanents you control by tapping them, adding an amount of mana.
Resolve the second copy of
Unstoppable Plan's trigger, untapping all nonland permanents you control.
Repeat from step 2.
Notes
The mana cost can be reduced depending on how much mana you produce in step 2 before activating
Mister Fantastic on the first iteration.
Results
Infinite mana nonland permanents you control can produce.