1. The Rings

Somewhere, deep in space, a black colored ring has almost completed its journey to its new wielder. In a fraction of a second, the ring slips itself onto a single, floating, bodyless finger. A deep voice coming seemingly from the ring boomed,

"PERFECT CELL OF EARTH. RISE."

Just then, three other rings; one green, the second blue and the third indigo, were also making their way to their new owners. The green and blue ones arrived on Earth, while the indigo ring was headed towards the Northern Kai's planet.

As usual, Vegeta was doing his daily gravity training routine. He was just finishing a set of 9,000 one-armed push-ups, when something crashed through one of the chamber's windows. It was a glowing green ring, and before he could react, it latched itself onto his finger.

"Prince Vegeta of Planet Vegeta, You have the ability to overcome great fear. Welcome to the Green Lantern Corps."

Trunks was also training. Specifically, he was practicing his swordplay when a blue ring attached itself to his finger.

"Trunks Briefs of Earth, you have the ability to instill great hope. Welcome to the Blue Lantern Corps."

Goku was on King Kai's world, polishing his skills. At the particular moment, Kamehameha waves.

"Ka... Me... Ha... Me..."

Normally, he would've fired it, but he sensed something coming. Fast. The next thing he knew, an indigo ring was on his finger.

"Kakarot of Planet Vegeta, you have the ability to feel great compassion. Welcome to the Indigo Tribe."