Getting 2/2s simply for playing Magic is a strong ability on its own, and opens up options for mana ramp, Voltron (making 1 creature super strong through powerups), Curses like Curse of Opulence for table politicking, and several other cool, unique effects that Auras can bring to the table as you build a token army
If you do, you gain 5 life
"When they no longer trust their senses, that's the time to strike." So the 7-attack statline and the First Strike keyword represents the archmage summoning the wall attacking the opponents that are confused
The one weakness is that opponents might be able to access some of the same spells as you if they also play a Dauthi Voidwalker, because it only looks for cards belonging to opponents that have a void counter on them
Getting three counters each time you gain life is huge, and can easily spiral out of control with a lot of Lifelinkers