Actually, he wasn't depowered. Thanos was using his power against him.
Depowered Tyrant refers to Tyrant lacking his original near-Galactus strength levels. That is the Tyrant Thanos fought.
uhm tyrant isnt much
Ahem... I’m inclined to insult the intelligence of this post because, I’m sorry, saying Tyrant isn’t much is just...not intelligent.