Haunted Plate Mail

Equipped creature gets +4/+4. {0}: Until end of turn, this permanent becomes a 4/4 Spirit artifact creature that's no longer an Equipment. Activate only if you control no creatures. Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o6n1j3v4vpb1hfj873mwt.