ever since sirius left, number 12 grimmauld place wasn't the same.
the monotony started looming over the people in the house again. everything seemed to be going slower, or as if it was replayed over and over again, a vicious circle that it was almost impossible to get out of. when sirius was still there, every single day, there was something to laugh about. in regulus' eyes, sirius had that strange ability of making a bit of fun in even the most boring activities.
the portraits of the members of the noble and most ancient house of black watching over you, every movement, every step, judging silently. sirius used to cover them up, regulus thought, and a smile ghosted over his face as he remembered the shouts of indignation of people that were once family as no one could see them, no one could hear them.
and now, that sirius was gone, regulus was the heir.
it was hard to play-pretend, a role that seemed to never be yours entirely, something that you had to do because another disappointment would stain the noble name of the family that you were destined to be a part of. you had to meet up people, vile people, strangers, that were only other pawns in a never ending game. you played, and played, and when they didn't need you in it anymore, they haunted your dreams and the game stopped for you, because they'd vote you out of the game.
that was what being a heir was for regulus. a never ending game. until someone said "checkmate."