Ethan is other one of the colonist along with Lisbeth who were aboard the Legato with the understanding that they would by colonist researchers. Their spacecraft the Legato was diverted and arrived along side the Sulaco which was enroute to Fury 161.
Reference stats table.
Appearances in the following;
Aliens: Colonial Marines
Ethan dies soon after being attacked by a face hugger at the start of Lisbeth's mission.
The events of the game are set between those of the films Aliens and Alien 3 but diverge from the film Aliens and over lap the film Alien 3.