Will of Nebiros

Tio has always been a naturally lively person; it's a trait inscribed into his very soul. The Will of Nebiros mutation allows the echoes of that liveliness to travel across the bonds his spark creates and enter his thralls, which over time causes them to develop a shadow of a personality similar to his own and become capable of a small level of independent thought.

This mutation only takes effect with thralls that are imbued with wells or often animated, and only those that are not imbued with a soul of their own (so no Revenants or Stonehearts).

• During the first cycle of animation the thrall slowly starts to move in a way that resembles Tio: they may walk like them, begin to prefer using their right hand, and make the same unconscious gestures that their master does.
• During the second cycle the thralls become able to convey simple emotions via sound or even basic words, following the speech pattern as Tio.
• During the third and final cycle the thrall becomes competent at speaking and starts to fully act like Tio; becoming able to have opinions, hold proper conversations, and even make small independent actions (such as investigating a noise or fetching a nearby item, but not so far as to take it upon themselves to complete a complex task or leave their assigned location to do something) so long as they do not directly conflict with their instructions. Despite their unusual actions these thralls still don't actually feel anything besides their hunger for life, they are merely going through the motions imprinted into them.

This mutation has the benefit of granting Tio's thralls the ability to act with a small level of autonomy and making them more interesting company, but has a number of drawbacks.

• The first is that any thrall that undergoes this process has a higher chance of rebelling, particularly if Tio orders them to do something or interact with them in a way that he would have disagreed with before becoming a necromancer. They also don't appreciate being reminded that they are dead, almost as if they're trying to forget what they are...
• The second is that these fleeting shadows of humanity make them capable of committing human errors. Social skills such as persuasion, intimidation and seduction can influence and distract them; they might instinctively step back when an opponent scares them, forget to keep a lookout when approached by a pretty lady, or be persuaded that their instructions should be interpreted a different way. If it would work on Tio, it will work on them too.
• The third is that the thrall does not have Tio's memories, nor do they possess any of his skills of the ability to learn new ones. They are still no more capable as servants as they would be normally.
• Additionally, for every thrall that reaches its final cycle, an eery black runic mark similar to his Eye of Nebiros appears somewhere upon Tio's body that leeks a thin current of necrotic miasma, and the patches of skin around these marks turn grey and corpse-like. These marks are caused by a dense undercurrent of miasma forming into a pattern beneath his skin which interferes with his body's natural illusion. Unlike the Eye of Nebiros these marks can be hidden by clothing, but will not fade for as long as the thrall it represents remains animated, even if it is no longer under Tio's control.

Approval here and here