Since Issei's codename was "Baldr" and the god Baldr was laid to rest on the Hringhorni I wonder if there's a connection between Issei and the Hringhorni, like he was involved in a previous mission with it
We also know that Issei was killed by a crossbow(wielded by an anomaly?), which actually matches that Baldr was killed by an arrow made by Loki(Baldr had been made invulnerable to all things except Mistletoe, and the gods had fun throwing things at him because they just bounced off, so Loki was able to make the arrow out of mistletoe and have Höðr, Baldr's blind brother, shoot him with it)
The one who avenges Baldr is actually one of Odin's other sons(who grew to adulthood overnight and killed Höðr) and Baldr wasn't allowed to be revived because one person(presumed Loki in disguise) refused to weep for him with everyone and everything else in the world so he can't come back til Ragnarok.
I can kind of see a parallel between Váli(the son who grew up overnight for revenge) and Alan in the way Alan avenged Issei by killing Dante, and the way he kind of had to grow up fast? So I wonder if Dante will also parallel Höðr in that he'll have killed Issei by accident. Like he killed him but it was because the anomaly did something to trick him into it--like he couldn't see or he disguised as him or he got ahold of the crossbow which was the anomaly's weapon and the crossbow acted of its own accord while in Dante's hands or something.
But most of all I wonder if Issei also has connection to the Hringhorni considering his codenamesake. :|a
(honestly this thought was going to be about Yevno but then i got distracted because i realized i'd mixed up Balor and Baldr lol. very different guys!)