Deal combat damage to an opponent using Myr Battlesphere, triggering Impostor Syndrome, creating a token copy of Myr Battlesphere.
When the Myr Battlesphere token enters, it triggers, creating four 1/1 Myr artifact creature tokens.
Activate Time Sieve by tapping it, sacrificing the four Myr tokens and sacrificing the Myr Battlesphere token, causing you to take an extra turn after this one.