Before I go and fully develop a character around it, I want to make certain this power works.
The ability is essentially complete control over all himself in the body and power sense. He can control the speed at which his cells replicate, heal by hastened regeneration and alter and rewrite his DNA at will. This enables him essentially change what he is genetically-grow new appendages or completely change his species-and, theoretically, enables him to write in other abilities into himself. This latter technique, though, can only be used once his body has learned the genetic code for an ability, which generally requires ingesting genetic material (assuming the ability is carried in their genetics, rather than something else) granting the ability. This generally means devouring some or all of the original carrier and comes with the inherent limitations both of the original use on top of his own. Beyond this, most ability genes tend to conflict or require the same point in the genetic sequence in him, making using multiple simultaneously difficult to impossible.
The major weakness is that he has to obtain sufficient energy and nutrients to do this; increasing the rate of cell growth means increasing metabolism and growing entirely new body parts or such means ingesting quite a great deal, pounds on pounds while also taking into account waste, energy efficiency and so on. While he can, obviously, improve his ability to digest food and such above usual human levels, he has to actually get said food and take the time to digest it-meaning that if he were to grow another appendage, for example, he will have to devour the necessary nutrients to do so-and then again to grow back to his default. This means that doing much with his abilities other than healing generally takes time and a lot of eating-and it often adds up toxins faster than he can remove them, and the ratio is worse the faster he runs it, increasingly pushing him closer to Ashing. For other 'abilities' taken on, he generally has to expend more physical exertion than the original on top of the process necessary to rewrite his genetics to use it, given the base physical nature of his ability.
In addition to/besides that, for a character with the ability above or another, I am wondering if I may play a character who is/was a Eugenics experiment by the Hands of Science, the Founding Family or some other nefarious group as an attempt to make said 'perfect being'?~<3