If Cryptic Trilobite has any +1/+1 counters, activate Cryptic Trilobite's first activated ability until it has no +1/+1 counters, adding ({C} magic symbol) ({C} magic symbol) that can only be spent to activate abilities each time.
Activate Altar of Dementia by sacrificing Cryptic Trilobite.
Cryptic Trilobite's undying ability from Mikaeus triggers, returning Cryptic Trilobite from your graveyard to the battlefield with a +1/+1 counter on it.
Repeat any number of times.
Resolve all Altar of Dementia abilities, milling any number of players any number of cards.
Results
Infinite colorless mana that can only be spent on activated abilities.