ONE OF MANY
ONE OF MANY, NE UNDEAD
One of Many is a collection of undead spirits crammed together into the Spirit Husk of what was once Okku the Bear God. Acquiring One of Many as a companion requires that you devour Okku's spirit at the conclusion of Act I, and then invite the Many trapped in the Crematorium of the Death God's Vault to enter the Spirit Husk left behind by Okku.
One of Many can be a powerful and versatile companion that gives you the option of changing it to your choice of three different classes. The dominant spirit of One of Many is the Child, with the result that One of Many's default class is Rogue. The Child is useful in subterranean dungeons with traps, as well as fights where he can sneak up on vulnerable targets and inflict hideous sneak attack damage on them. Since he has the Epic Precision feat, he'll still be able to inflict half sneak attack damage on the many enemies in Mask of the Betrayer (e.g. undead, elementals) that would otherwise be immune to sneak attacks.
If you obtain a minimum of +25 influence with One of Many, you will then have the option to have the Brute take control of One of Many. Doing so will change One of Many's class to Barbarian. The Barbarian will thrive in fights where he will have to face his enemies head on, and where there may not be the opportunity to flank or sneak attack enemies that the Child would thrive in.
If you allow One of Many to devour the spirit of either The Sleeper of the Hag named Gulk'aush in the Skein, One of Many can then change to the Madwoman. The Madwoman's class will be Warlock. I did not find the Madwoman option particularly useful. One, she did not have the Eldritch Chain shape, which I consider bread and butter for any Warlock. Second, she wastes her epic feats on the epic spells (e.g. Damnation, Entropic Husk), when they are in my opinion far better spent on Epic Eldritch Blasts. For the reason why, see my approach to developing an epic Warlock during the Storm of Zehir guide.
Stats
Skills
As the Child, One of Many emphasizes:
Feats:
As the Child:
Invocations:
One of Many has access to the following invocations after changing to the Madwoman:
Inventory
One of Many, whichever spirit takes control, is unable to equip any items whatsoever.