Originally posted by BrolyBlack
No, he can take their powers at any time he wants.
Tyrant was going to kill Galactus as easily as cyanide would take the life of a human. He was saved by Morg via Ultimate Nullification. They'd destroy Galactus. Galactus made Tyrant to be his equal. Tyrant exceeded his original power levels by gathering Orbs of Power which placed him well above Galactus standard well fed power levels. It's canon.