SAMURAI JACK AND STEVEN UNIVERSE MAY JUST TAKE PLACE IN THE SAME UNIVERSE. IN SEASON ONE OF SAMURAI JACK EPISODE 12 JACK HAS TO RETRIEVE THE MYSTICAL "NEPTUNE JEWEL" WHICH HAS CONTROL OVER ALL THE WATER ON THE PLANET. AND IT LOOKS LIKE THIS:
NOW LAPIS' BACK HAS HER JEWEL:
THEY ARE THE SAME, AND WE KNOW THAT LAPIS CAN CONTROLL ALL THE WATER ON THE PLANET BECAUSE SHE DID SO.
SO AKU TAKES OVER THE PLANET AND BY THAT TIME LAPIS BECOMES THAT OF A GODDESS TO PROTECT THE OCEANS OF EARTH (SHE COULD BECOME THIS POWERFUL THANKS TO FUSING WITH JASPER AND HAVING TO FORCE THE ENTIRE OCEAN DOWN UPON THEM.) THE OTHER ELEMENTALS IN JACK'S EPISODE COULD BE PART OF THE SPIRIT PLANE IDK. BUT THERE IS A CONNECTION SEE? SEE~!?