I accept this as a bad idea, but you should make the latter (NPCs) worse, that:
-Said NPCs will laugh evilly (or at least an annoying laugher, like Playtime's laugher in Baldi's Basics in Education and Learning, because that would make Meggy, from SMG4, sound better and the same with Bubsy).
-You and your device will also be teleported to the sun (in real life) after dying to them.
-Said NPCs will also say "HOW DARE YOU RETURN, YOU MUST DIE!!!!" once you return from the grave as another character with the same name as the previous one.
The Other ideas for Chaos-mode worlds are:
-Every overworld music is sung by a yelling 5-year-old, at Earsplitting volume rates.
-Softcore and Mediumcore players are now locked until you defeat the final boss in Chaos mode.
-A final boss is added: Dracon (invincible boss with 1 trillion total health, damage, defence, speed and knockback resistance. Has four fire-spitting heads with 250 billion HP that must be defeated, so it would be a flying head. Dies after you kill its last head).