Reckoner Bankbuster and Coretapper do not have summoning sickness.
Reckoner Bankbuster has exactly one charge counter on it.
({2} magic symbol) available.
Steps
Activate Reckoner Bankbuster by paying ({2} magic symbol) , tapping it, and removing a charge counter from it, drawing a card, creating a Treasure token and a 1/1 Pilot creature token.
Intruder Alarm triggers, untapping all creatures.
Activate Coretapper's first ability by tapping it, putting a charge counter on Reckoner Bankbuster.
Activate Ashnod's Altar by sacrificing the Pilot token, adding ({C} magic symbol) ({C} magic symbol) .