His meltdown is inevitable. The question then becomes, will we all go down with him, or salvage ourselves at the same time as getting him some real help?

The sooner we do it, the more damage we get to prevent, too.

I specialize in treating those with sociopathy, and I find that they can always be helped in some way—but just to keep them from destroying others and themselves is help. Ordinary people should not try this; keep your distance, and limit the time you spend on them, if you must.

Correct management is containment and limit setting. It is NOT giving them power, allowing them plenty of opportunity for murder, failing to hold them accountable, and overlooking their behavior to be polite. All this is WRONG management that will vastly worsen their behavior.