I don't know about the skybreaker but in the earlier versions I found 5 followers :
-Giant Rat : Sewers Dungeon - Floor 5.
-Raving Fan : Outside the Town's boundaries. Don't make it leave the party too much though, as its leader will become stronger each time its defeated.
-Green Slime : Slime Dungeon - Random Floor. Be careful, though : You can only increase its stats by using Potions and the Potions' effects dissipates after a fight.
-Mad Chimera : At the City's Port (Last time I checked).
-Foreman : Outside the Crystal Cave Dungeon.
I'd give you the solutions to recruit them all but I feel like it'd be unfair spoilers...