Neurok Transmuter

{U}: Target creature becomes an artifact in addition to its other types until end of turn.
{U}: Until end of turn, target artifact creature becomes blue and isn't an artifact.

Simic Guildmage

({G/U} can be paid with either {G} or {U}.)
{1}{G}: Move a +1/+1 counter from target creature onto another target creature with the same controller.
{1}{U}: Attach target Aura attached to a permanent to another permanent with the same controller.

March of the Machines

Each noncreature artifact is an artifact creature with power and toughness each equal to its mana value. (Equipment that's a creature can't equip a creature.)

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.

Indestructibility

Enchant permanent
Enchanted permanent has indestructible. (Effects that say "destroy" don't destroy that permanent. A creature with indestructible can't be destroyed by damage.)