Assassins dealing damage is not lethal to opponents in this instance but lets you bolster your ranks with their cards thanks to the Cloak ability
Senseis Divining Top, which was already a format staple, got even more popular after Kaldheim for Birgi storm lists and Kamigawa: Neon Dynasty for its combo potential with The Reality Chip
Good ETB effects are rampant in EDH so those activated abilities make this a good skill testing commander, because Livio is much more dangerous in the hands of an experienced player than in a newcomer
Astrologians Planisphere might actually fit well in a more tempo or artifact-heavy UW build, possibly with Cryptic Coat in the mix
This is really only going to work super well in Black/Red and Blue/Red, because you need that Chapter I to kill something, otherwise you're playing a very mediocre card
To support that theme, it contains small evasive creatures that can get through your opponents' defenses and get upgraded to Ninja-hood