Epic Games took a big step with conversational AI when it added a new version of Darth Vader in Fortnite that could speak with players. But later this year, any creator using Unreal Editor for Fortnite (UEFN) will be able to make their own AI-powered characters with the same underlying technology behind Vader.
During the 2025 State of Unreal keynote, Epic revealed that a new tool in UEFN called the Persona Device will allow anyone to create non-playable characters (NPCs) with AI-driven personalities. The company showed this in action with an internal demo where the player has to talk to a robot named Mr. Buttons. Epic Games executive vice president Saxs Persson said this was meant to show how the Persona Device can “enable emergent, reactive gameplay for creators and deeper experiences for players.”
Within the demo’s Verse code (the programming language used in UEFN), the AI prompt that defines Mr. Buttons’ personality describes it as a “mysterious cosmic entity” with infinite knowledge and curiosity, and that it must respond to the player with “comedic finesse.” Mr. Buttons appears as a floating metal sphere with a glowing eye, and it has one singular purpose: to get you to press the big red button at the center of a catwalk.
You don’t know what will happen if you press the button, and if you ask Mr. Buttons about it, it’ll give you vague but playful answers. If you comply with the robot’s request, the screen darkens, and the demo is immediately over. But as with the AI Darth Vader, you can try steer the conversation into other topics or even probe deeply into why it wants you to push the button so badly. It uses filler words lik …