Master Transmuter

{U}, {T}, Return an artifact you control to its owner's hand: You may put an artifact card from your hand onto the battlefield.

Master of Etherium

Master of Etherium's power and toughness are each equal to the number of artifacts you control.
Other artifact creatures you control get +1/+1.

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

{T}: Put a +1/+1 counter on each artifact creature you control.

Artifact creatures you control get +2/+2.