Name: Healing Factor (In a similar manner of superhuman endurance)
Type: Result of experimentation. Manipulated DNA-based ability(?)
Rank: B-S?
Abilities Gained: In a manner of speaking, Roki is really hard to kill. When injured his wounds don't fully heal but they actually close pretty quickly (taking two posts) but prior to this, his skin is hardened to more of an extent making him more resistant to injury. Thus, lessening the damage from some weapons such as projectiles but receiving similar damage to getting hit with sharp weaponry when applied with great force. Basically think of him as having dragon scale skin but to a lesser degree.
As for major injuries, his body goes into a comatose-like state where his body will use 50% of his Chakra reserves to heal himself (as mentioned below the process takes a full day to complete). I'll be free to elaborate if need be.
However, as a self defence mechanism when his body enters the comatose-like state his skin hardens some more so that enemies are less likely to take advantage of his new found state.
Disadvantages: When Roki is revived from 'near' death or fatal strikes (which takes a manner of days) his 'other' personality takes control for a brief moment. This other personality is pretty much Roki's polar opposite, being sadistic and blood thirsty (If you having trouble picturing this think of it as a sort of mix of the Kyuubi taking over Naruto's body mixed with the personality of Ogichi from bleach).
Another obvious disadvantage of this is if his body goes into the comatose state (in which he actually looks like he's dead with the only give away is the fact that if someone were to contact his mouth or nose then they'd realise he was actually breathing at a less obvious rate) he's prone to attack similar to the way a person sleeping is more vulnerable to attack.
Other Effects: As mentioned earlier his other personality (or rather a darker side of his personality) takes control after he's been awakened from comatose state. The give-away of this personality being dominant is that his eyes take on a red tint and will usually glow. Ow erm as part of elaborating on this alternate aspect of his personality I'll delve deeper into it in my character application.