They will rise up and serve again, and again, and again.
I noticed that the Risen include warriors from every army list but the Devout, but the Devout Swordsmen's fluff certainly implies that the Devout will raise their own followers.
Here are stats for Devout Risen Swordsmen and Great Swordsmen.
RISEN WARRIORS (8-16 made from the lists below)
Devout Swordsmen Risen (0-8)
Devout Great Swordsmen Risen (0-8)
Immune to hand held Missile Weapons
Devout Swordsmen Risen are each armed with a Dark Sword and a Shield.
Devout Great Swordsmen Risen are each armed with a Two Handed Sword.
These Risen can be added to a warband of Risen of other factions like normal Risen rules. If a player deploys these Risen using models of Swordsmen and Great Swordsmen, he or she must let his opponents know that these represent Undead Units.