Crusader was the personal transport of Siva Kai, a Nagain mercenary in the employ of Wayland's Wilders. Kai had already spent some time modifying the ship before joining up with the Wilders, and their chief technician, Syd N'aanzi, assisted him in further improving the fighter.
Obviously, the first thing that needed changing was the size of the cockpit, as it was designed for the small frame of a small, stocky Utai, rather than a tall, lanky Nagai such as Siva. The refit also forced him to replace the fighter's original dual-reactor power system with a miniaturized conventional power source, albeit a rather robust one which actually increased the ship's overall energy output.
The increased energy supply allowed for further modifications. The twin laser cannons were swapped out for a quartet of N'aanzi's trademark pulse lasers, and he somehow managed to cram in a pair of proton torpedo launchers as well. A shield generator was taken from a Delta-7 interceptor (made stronger by the powerful generator driving it), complete with its ability to automatically strengthen areas of the shield that were under attack. The Aethersprite's sensor suite was also co-opted, and its sensitivity was refined to make up for Kai's lack of Force sensitivity.
One of the craft's most unique modifications was the addition of a prototype combat/targeting computer "acquired" from the Corellian Engineering Corporation. The highly advanced machine allowed for a greater number of vehicles to be acquired and tracked simultaneously, and would even direct the weapons linked to it to focus on known weak spots of whatever they were aimed at (e.g. the exposed shield generator of an Incom I-7 Howlrunner).