Myr Welder and Biotransference on the battlefield.
Empowered Autogenerator and Leech Bonder in exile (exiled by Myr Welder).
Myr Welder does not have summoning sickness.
Steps
Activate Myr Welder using Empowered Autogenerator's ability by tapping it, putting a charge counter on Myr Welder and adding ({U} magic symbol) for each charge counter on Myr Welder.
Activate Myr Welder using Leech Bonder's ability by paying ({U} magic symbol) and untapping it, moving a counter from a creature onto another creature.