Being used as a main character in the first game of the trilogy he plays quite a large role in the series. What happened to Nomad after the first game? The island was vaguely mentioned in the second game but they never mention Nomad.
There is a graphic novel / 6 comics which tell a little bit about what happened between crysis and crysis 2.
Quote From Wiki:
SPOILER FOR THE COMICS
Nomad, who was injured previously, is badly wounded yet again. Once on board the boat, he is injured with a drill and given a painful awakening in order to pressure Prophet into revealing vital information. Nomad is then taken away for medical treatment. When Admiral Morrison's nuke hits the island, the EMP blast unlocks the suits. Realizing that Hargreave has nothing to do with the crew and that the CIA is responsible for this ordeal, Nomad appeared to sacrifice himself by jumping in front of a rocket intended for Prophet and Psycho.
You can go to Nomads Wiki Page here
In Crysis 3 it is said that all are dead except Prophet and Psycho. So we can assume that what happened in the comics indeed was carried through to the sequels.
Sorry to bring up an old thread, but there is some missing information from Lokuzt's otherwise perfect answer. Quoted from the Wiki(link)...
"After collecting all data pads in Crysis 3, a new file appears that states that Nomad is alive and is being hunted by a Nanosuit operator known as "Lockhart." Although exactly which Lockhart this refers to--the deceased Commander Lockhart, his apparently dead nephew, or a new character--is unclear."
Hinting that Nomad somehow survived the rocket attack and is still operating in some capacity.