Turn-based PvP duels. Challenge by aiming at another player's Main Cubee (they must have requests open — toggled in the pet menu's Behaviour tile). A Yes/No title prompt follows; then alternating cast turns on a visible turn timer; win/loss is announced to both sides, and cancellation paths exist.
Wins as Main feed the ᴠᴀʟᴏᴜʀ badge and the WIN_BATTLE quest action.
The full turn-by-turn ruleset (exact turn seconds, what ends a match) is still being confirmed against the live server and will be expanded here once verified.