Unlike the Celestial Deer Corner, the Golden Flame Corner had hubs on both the celestial and dao floors while those hubs of the celestial deer corner were either already taken over, or left dormant. This key was the best way to take control of them. Plus, that didn't mention its use militarily.
Dyon was about to sigh a breath of relief when the key suddenly tried to fly away at blinding speeds. Madeleine's expression changed. How could she forget? The most powerful Clans and Sects placed contingency plans on their keys in case anything unexpected, like the death of the wielder, happened. The only reason that Dyon's key just floated up, waiting for anyone to take it, was precisely because he didn't have such a plan in place. It was no wonder Titus left the key in God Goldeen's spatial ring, he knew this would happen.
However, did they really expect that their contingency plan was enough? Dyon was a Planet Lord now, albeit only in power and not in comprehension, it was enough!