The final confrontation with Sonny Forelli takes place during the mission 'Keep Your Friends Close...'. This is the climactic battle of the game, involving a full-scale assault on your mansion by Forelli's mobsters. It's a multi-stage fight that tests all your acquired skills and resources. Prepare with maximum health, armor, and a full arsenal of heavy weapons.
Phase 1: Defending the Safe
Forelli's men will first attempt to steal money from your safe. Position yourself on the upper floor overlooking the safe. Use an M4 or Minigun to mow down the waves of mobsters. They will come from multiple entrances, so keep an eye on your mini-map. Don't let them reach the safe, or you'll lose money. Collect health and armor pickups from around the mansion as needed.
Phase 2: Confronting Sonny
After the safe is defended, Sonny Forelli himself will appear, accompanied by more bodyguards. He is heavily armed and can deal significant damage. Use the mansion's layout to your advantage, taking cover behind pillars and walls. Focus fire on Sonny, but don't neglect his bodyguards. A Rocket Launcher can be effective against groups, but save some ammo for Sonny. Keep moving and utilize your most powerful weapons. Once Sonny is defeated, the game's main story concludes.