Another thing that was briefly mentioned by Rin in Saber's route was the fact that there was a Servant who was said to share its life force with its Master. This was actually a reference to an early concept we had for Berserker. The idea was that Berserker and Illya basically shared a life pool, which essentially meant that targeting Illya instead of Berserker was a futile tactic. As long as Berserker was alive, Illya could not truly be killed. Of course, all logic dictated that Illya and Berserker formed an invincible pair in this case. It didn't take us long to realize that this would completely destroy any semblance of balance in the game, so the idea was ditched.
