If you want a that could be added to such a fan-made or modded version of DB Xenoverse 2 for PPSSPP, here’s a creative idea: Feature Name: "Time Rift Survival Mode" Concept: A rogue-lite, endless survival mode where the player fights through unstable time rifts that randomly generate different battle conditions, enemy waves, and environmental hazards.
It sounds like you're interested in on the PPSSPP emulator —but just to clarify, Xenoverse 2 was never officially released for PSP. However, fans have created mods or lite versions for PPSSPP, often based on Dragon Ball Z: Shin Budokai or Tenkaichi Tag Team with Xenoverse 2 skins/moves. dragon ball xenoverse 2 ppsspp download