Q: Word describing desperate fighter I am looking for a word that describes the following person:

Someone who is involved in a formal conflict, has no obvious route to victory, no plan, no immediate hope of any significant gain; yet is not willing to surrender or negotiate peace (due to ideology or dogma), and would rather attempt any action to (even insignificantly) damage the adversary, even if that was to his/her own peril.


A: "Kamikaze" is a Japanese word meaning "divine wind", that has an English meaning of "suicide pilot".  It got this meaning in English because during World War II, the Japanese called naval pilots who deliberately flew their planes into American warships "kamikazes".
"Juramentado" is a similar word for Moro jihadis who made suicidal sword attacks.
"Berserker" is a similar word for Viking warriors.  The Viking berserkers often survived.
"Desperado" is a similar Spanish word for a desperate fighter, especially in the context of the American "Old West".
"Diehard" and "holdouts" might be the closest English words that are not "borrowed" from another language.  In the "Die Hard" movies, Bruce Willis' character was victorious, despite very long odds.  "Diehard" is also used for a brand of long-lived automobile batteries, and for people who stay in a game, business, or career after most others have quit.  The last opponents in a siege or war to surrender might be called "holdouts".
Most Americans would understand kamikaze, berserker, desperado, "diehard", and "holdout".

A: Crusader or zealot might serve here. It certainly fills the requirements for "dogma or ideology." It does not imply that they have no plan or hope of immediate gain, though. 
Radical might also serve. It has a more political connotation. It does not necessarily imply that the subject is a warrior in the traditional sense, however. Rebel might fit if the person in question is fighting against a governing body.
Regarding Jasper's suggestion of "berserker," this is a decent one but once again it's missing a piece of the definition: ideology. Historians aren't sure if "berserkers" actually existed, but they are described as Norsemen who entered some kind of rabid state of mind during the fight. One of the most popular theories is that they used narcotic plants, but no one is sure how they did it, if they existed. Therefore a berserker is a warrior who will stop at nothing to hurt the enemy, but does not necessarily have any form of ideology behind his actions; in fact, they are often portrayed as sadists who enjoy the thrill of killing.

A: wild
is my answer. With filler words. 
