(Refer to Polaris for the backstory)

Unlike his twin, Anubis is far less trusting and naive, almost to a fault (he's envious of those who are naturally so kind as much as he low key despises them)
He expects the worst and doesn't hesitate to do whatever he needs to keep him and Polaris (especially Polaris) safe no matter the cost
You wouldn't know it tho given he's a big charmer who's perfected the act of imitating his twin