Something with far less than 100 men left in total in the universe, with no officers or support staff left.
Mutated by a fluke ostracising them from any legitimate restocking base (but still on the goody side)
(
http://warhammer40k.wikia.com/wiki/Legion_of_the_Damned )
Compare to the lost and the damned, which is everything non marine in the universe which rebels,all the civilian populace swayed into action, everything in the universe under sway of a cult or just who want to watch charly chaplin films after imperial kerfew, everything in the universe basically not covered by being eaten, genetically engineered by the emperor or imperial guard.
It is the 99% Imma gonna set up a tent in the GW carpark..
No, but the unit could do with a major rules fix or points halving.