Persona 5's Velvet Room Theory
Given the nature of the Velvet Room servants, by P5, Margaret would have already left the Velvet Room (Theo too if you still count him). Thus, Igor feels all alone, and falls to a depression.
The P5 protagonist finds him lost and drunk in some sort of dark alley, since he has apparently crashed the last Velvet Room, the limousine, into some sort of tree between dreams and reality.
Thus, when Igor does fusions, most tend to go wrong since he's still kinda drunk. The money you give him for the compendium goes to Igor's "Buy a new Velvet Room" fundation.
By the end of the game, he has collected enough money to buy himself a tent, and becomes a camper. Thus, the Velvet Tent is born.
Any resident of the Velvet Room in Persona 6 is called a boy scout, and Social Link cards are replaced with merit badges.
Somewhere, Philemon is disappointed.