The ??? modifier in FNTD2 is an unlockable Boss Raids modifier, and the user guide says you can get it by reaching 1.5x Difficulty or by unlocking the OMC quests through a wave 100 clear with someone who already has the modifier, as long as they host the Boss Raids match.

What it does

It appears to be a special modifier option that becomes available once unlocked, rather than a simple stat buff described in the source I found.

How to unlock it

  • Reach 1.5x Difficulty.
  • Or beat wave 100 with a player who already has it, with that player hosting the Boss Raids match.

Note

The source I found explains how to unlock ???, but it does not spell out a deeper in-game effect beyond it being a selectable modifier.

Would you like a plain-English explanation of Boss Raids modifiers in FNTD2?