>>4192868Rin and Illya are actually quite similar to one another in FSN if you think about it. Both are heirs to one of the founding families of the HGW and both are raised with the burden of having to one day fight in it. Their arcs both revolve around their starting out in opposition to Shirou and wanting to fight him, to steadily growing closer to him and eventually becoming better people due to his influence. Both have a softer and more good-natured personality hidden under a cruel and even murderous exterior. Both Rin and Illya play a pivotal part in Shirou's arc in UBW and HF respectively (which can be called "their routes") when they impart their own personal way of viewing the world onto Shirou, which leads to his overcoming his issues; Rin when she convinces him to love himself in Your distortion, Illya when she convinces him he should save Sakura.
