It's been 1 thousand years. Humans are doing human stuff in and out of Earth now that their society has extended into the stars. All gems have been integrated into human society for many many years and have been getting by with each new human friend they make, along with their fellow gem friends.
Off in a cave in a distant mountain dwells a rumored wizard, who saw the world almost end and took off beyond the stars to bring a family back together in order to save his beloved planet. You decide to investigate the mountain out of curiosity if the rumors were true. Equipped with nothing but one word to draw the wizard out, you nervously approach the cave entrance and speak aloud "Steven". Silence. You wait a moment for any sound or voice, when you hear the faintest steady tapping. It grows just a little closer with every beat of your racing heart. Finally, you hear a small chuckle.
"Steven, huh? Haven't heard that name in a while" says a shadowed figure as it takes shape in the darkness of the cave. You hold your breath as your watch the rumors evaporate into truth, as the withered old wizard emerges into the light of day. He had a stunning pink glow about him, far from human despite his deep set wrickles and hunched posture as he leaned onto what appeared to be a strong wooden staff.
"These days I simply go by Mr. Universe".
Yep another laaaaate night sleep deprived theory.
Human Steven lived a nice long human life. Upon passing away, his gem half lives on. It's not easy since he bears the weight of his human experience on his shoulders with each passing millennia. So Mr. Universe likes to keep himself entertained as the rumoured old wizard in a mountain. Truthfully he has a warp pad inside said cave, and doesn't actually need to appear like an old man, he just prefers that form since it was how he looked just before losing that human part of himself.
Basically he is Doctor Who.
