Elder Kai (Old Kai, canonically) serves as a shopkeeper NPC.
Like the majority of characters, Elder Kai is purely based on Old Kai from the anime and manga. He wears the same Kaioshin uniform and has a white mohawk.
Elder Kai appears on the map Earth, in Central City's market square, in his shop. There, he can unlock players' potential for 10,000 Zeni. The EXP his power-up gives is 100,000, which can be useful for new players.
For players in mid to end game, (above level 100), this shopkeeper becomes rather useless, as levels begin to reach the hundred thousands of XP, and eventually the millions. The cost is most likely on par with Hercule's 10k zeni for 250 Robux, as Hercule states, "Some players just want to buy their way to the top."
- In the earlier days of Final Stand, Elder Kai used to give out 10,000 EXP.