Soldevi Golem doesn't untap during your untap step.
At the beginning of your upkeep, you may untap target tapped creature an opponent controls. If you do, untap Soldevi Golem.
The information presented on this site about Magic: The Gathering, both literal and graphical, is copyrighted by Wizards of the Coast.
This website is not produced, endorsed, supported, or affiliated with Wizards of the Coast.