Due to some shipping irregularities with that year's annuals, Gambit's first published appearance was in the last chapter of Days of Future Present instead of his intended first appearance, Uncanny X-Men (1st series) #266.
Gambit became Death in X-Men (2nd series) #184. Death I is the embodiment of death, Death II belonged to a set of Horsemen that battled the Fantastic Four.
Gambit's powers are constantly operating on low levels thanks to brain surgery by Sinister. At enhanced capacity, Gambit generates a constant field of passive energy that he can expand outwards to charge any form of matter within his field of vision. He could control kinetic energy to a better degree in this state, generating far more explosive power than usual or simply incinerating his target. Using his increased powers generated an augmented level of bio-kinetic energy within his body as well, heightening his strength, agility, and reflexes to a certain extent.
As Death, Remy could produce a transmutator effect to change air into a noxious and lethal gas. He possessed this power between X-Men (2nd series) #185 and 200.
Gambit's real name was revealed in X-Men (2nd series) #8.