Lost Jitte and Gemstone Array have at least one charge counter on them.
Cryptic Trilobite and Crystalline Crawler have at least one +1/+1 counter on them.
({4} magic symbol) available.
Steps
Activate Karn's Bastion by paying ({4} magic symbol) , putting a charge counter on Lost Jitte and Gemstone Array, and a +1/+1 counter on Cryptic Trilobite and Crystalline Crawler.
Activate Cryptic Trilobite's first ability by removing a +1/+1 counter from it, adding ({C} magic symbol) ({C} magic symbol) that can only be spent to activate abilities.
Activate Crystalline Crawler's first ability by removing a +1/+1 counter from it, adding ({1} magic symbol) .
Activate Gemstone Array's second ability by removing a charge counter from it, adding ({1} magic symbol) .
Activate Lost Jitte by removing a charge counter from it, untapping Karn's Bastion.