Archibald_TK auf Warseer:
Regarding Bloodreavers, they truly are 20 per boxes. Unit size 10 minimum. Options are either Reaver Blades or a Meatripper Axe (basically both have the same stats but blades reroll 1 to hit and axes are -1 rend), no shield. There are 20 of each weapons (thought apparently only 10 different variants, so each has a duplicate), 36 heads (but same here, only 18 different ones x2) 20 are naked and 16 have masks.
They describe in the WD how Sigmarines are created, this is basically the same process as Space Wolves, including the feast before the transformation. Just replace any mention of genetics with magic.
Being constantly reforged nasty side effects are not limited to a change of personality, they can also change physically. Both lead to different chapters having some specificity. For example the Blackhammers can suffer from sudden destructive rage, the Hammers of Sigmar are unable to acknowledge anything as a victory unless it is total and absolute, Celestial Vindicators if three of them are part of the same vehicle squadron they can shoot a single apocalyptic blast... no wait I'm mixing up my rules here, Celestial Vindicators feel the unstoppable urge to avenge any exaction against innocents in blood. Overall they're nice chaps.