"A powerful detonation in Moscow." Putin's confidant killed

According to the TASS news agency, an detonation occurred on Monday morning in the lobby of the luxury residential complex "Scarlet Sails" on Lotniya Street in the northwestern part of the Russian capital. According to media reports, 2 people died and 3 were injured. Among the dead is the founder of the Armenian battalion "Arbat" fighting against Ukraine. A homemade explosive device is said to have detonated at the entrance to the building. The man was accompanied by safety guards. Who is Armen Sargsyan? Formally, he is the head of the Boxing Association of the alleged Donetsk People's Republic, and unofficially a politician of Armenian origin who formed the collaborationist battalion "Arbat". What kind of formation is this?