You blew me away mate. Hekireki was one of the 1st anime openings I saw in a long time.
Gotta leave some of my fave openings of anime or games of said animes here, 5 for this time, and it is the sickest one, I dunno why they don't make it like these anymore)
Pokemon Battle frontier jap theme (honestly this is the only pokemon ost i like)
My Dearest - Supercell -> Guiltry Crown Opening
Cadence - Takaaki Natsuhiro -> Yowamushi Pedal : New Generation Opening
Sakebe - Manami Numakura -> Mahou Shoujo Ikusei Keikaku Opening (Oh mate the deaths on this anime left a scar on me)
Teadrop - Bowl -> Yu-Gi-OH! Gx Opening (Best yugioh opening ever imo also best arc in all seasons made)