Sorry for the wall'o'text. Figured I need to do a proper intro for Jack, and his evil scheming ways.

For those questioning how he managed to give someone powers:
The operation was to tattoo marks onto Daniel. The tattoo forms a network, which uses kinetic energy to negate the impact of attacks. When an attack is performed against Daniel, the network releases a pulse of energy exactly equal to the force of the impact. As such, Daniel has become virtually immune to physical attack, gaining 'the power of Achilles'. Of course, one can still harm him by simply hitting him until the network runs out of energy, attacking him with something that can't be reflected with kinetic energy (lasers, heat, etc.), or by using Jack's kryptonite of course.

Speaking of which....

[@Regitnui]
Jack's weakness has been altered to be slightly more specific, as 'happiness' is a fairly vague and broad weakness.