DS9 returns to Bajoran politics and prophecies for this Sisko/Kira story - sort of a poor man's "Destiny" (from the prior season). The episode flirts with a lot of meaty material: Sisko passes the Emissary torch to another, Kira questions her future, a religious leader brings back an archaic idea, the Bajorans have differing opinions of how to handle this, and there's even a murder. (And if that's not enough, Kai Opaka makes her last appearance in the series). Yet most of the issues go unexplored, and there's a lack of energy behind what we do see. It's as if everyone is getting a bit tired of Bajoran spiritual beliefs and they're now just going through the motions. (The B story itself, about the O'Brien family dealing with change, is forgettable in its own right).
Special guest star Richard Libertini (as Akorem Laan, the new Emissary) does the script no favors. He's a weak antagonist with no gravitas or presence. Had David Warner played the part (as originally intended) it's likely Warner and Avery Brooks would have given the Akorem/Sisko adversarial relationship enough sparks to carry the episode; but Warner's wife didn't want "Accession" to disrupt a vacation and asked her husband to decline. What we're left with is underwhelming.