Мафия Alternative. Zombieland.

The night discussions have already been voiced; there's no point in repeating them.

Reinhard Klimmt (born August 16, 1942) is a German politician, former Minister of Transport and Construction. From 1998 to 1999, he was the Prime Minister of Saarland. As is known, Freemasons were stonemasons.

His Eminence Cardinal Reinhard Marx (born September 21, 1953, Geseke, West Germany). German Cardinal. Titular Bishop of Petina and Auxiliary Bishop of Paderborn from July 23, 1996, to December 20, 2001. Bishop of Trier from December 20, 2001, to February 2, 2008. Archbishop of Munich and Freising from February 2, 2008. Cardinal-Priest with the title of the church of S. Corbiniano from November 20, 2010. Reinhard Marx is the youngest cardinal of the Roman Catholic Church.

I'm a bit puzzled by the fact that there seems to be a method of selecting names here. But the connection between construction and Freemasons, and consequently with the "Delta" in general, is no less significant than the "Tox flower."
It is quite possible that this is a serial killer.

On the other hand, there is some similarity with this:

Black Heart of the Kabal

On the other hand, Calypso is the daughter of Apollo, who is symbolized by sunlight. If we discard the "Delta" and focus on the radiant, we can draw a connection. But this is an unlikely clue.

If we consider the "Delta" as a symbol of the church, we can add Neyru to the list of suspects because of her "Le Trublion."

That's all for now.

As the main suspects, I would still highlight Reinhard and Morning.