UT: Soul Ops Boss Rush Extended

Sans AUs Fighter 2 (SAF2) is a real-time PvP and PvE fighting game on Roblox set in the Undertale multiverse, developed by yuika shenanigans and launched in November 2024. Players choose from a roster of Alternative Universe Sans characters - Dust Sans, Swap Sans, Outer Sans, Error Sans, and many more - and battle each other or special boss entities in a 10-player server. Growing to over 6.7 million visits with a 92.3% approval rating in its first year and a half, it has become one of the leading Undertale AU fighting games on the platform. Best played with keyboard and mouse; a low-latency connection is recommended.

The core loop centers on picking a Sans morph, entering Free For All or dueling a specific player with /challenge, and accumulating EXP and Gold through fights. EXP is the primary progression currency tracked by a series of badge milestones stretching from beginner wins all the way to 10 million EXP - a grind that defines the long-term experience. Gold funds cosmetics and limited shop items in the lobby:

• ⚔️ Free For All (FFA) - open PvP where all 10 players fight simultaneously; killstreaks earn EXP fast
• 🏆 Ranked Mode - competitive format with overpowered characters like Outer Sans and H.I.M. banned for fairness
• ⚔️ Boss Area - special boss entities including THE ORANGE GUY and THE BLUE GUY spawn periodically; defeating them awards dedicated badges
• ⏳ Sigma Mode - event boss spawns on a 20-minute cycle; Menacing Dust Maxwell appears in this format
• 💎 Character unlocking - most characters require EXP thresholds; limited characters appear during seasonal events

The dusted kill mechanic references Undertale's lore directly - defeated players turn to dust. Characters like Final!Insanity feature a Phase 2 transformation, and the ultra-rare H.I.M. form triggers on a 1/150 death chance. A Rainbow Orb with a 1/100 spawn chance every 10 minutes awards the prestigious Seraphim Soul badge. EXP gamepasses double gain rates and stack with event bonuses but not simultaneously with each other.

SAF2 is the most actively updated Undertale AU fighting game on Roblox as of 2026, with seasonal content (Christmas 2024, New Year 2025, Halloween 2025, April Fool's 2026) keeping the character roster and event modes fresh. Comparable titles in the genre include Sans Multiversal Battles!, though SAF2 has surpassed it in active playercount and update frequency.