The number 13 is linked to evil and misfortune primarily through two tales: Judas Iscariot, the 13th guest at the Last Supper who betrayed Jesus, and Loki, the trickster god, who was the 13th to arrive at a feast in Valhalla, leading to chaos. This association fuels the superstition of
triskaidekaphobia (fear of 13) and combines with Friday (the day of the crucifixion) to create "Friday the 13th," a symbol of bad luck, though some traditions view 13 positively as a number of cosmic completion
Seems Loki also has a connection to 13