Koudelka (Is It Necessary?)

[The Ceej]

I currently own all three Shadow Hearts games even though I've only played the first and only about halfway through. I understand that Koudelka starts the entire series. I've done some research, but I can't seem to find how relevent Koudelka actually is to the Shadow Hearts series. I'm not asking if it's a good game. I'm asking if playing it will make playing the other Shadow Hearts games more understandable or enjoyable. Anyone played it? Anyone know?

[Vermachtnis]

It's not really necessary to play Koudelka. She does have a cameo later on in the first game and you go through the ruins of where Koudelka takes place. But I'm being vague cause I'm not sure how far you are and what counts as spoilers.

[The Ceej]

I'm not actually playing right now. I can't play two RPG's at a time. So, yeah. I don't remember exactly how far I got and I don't recall much about the game. So pretty much anything would be a spoiler to me. So basically, I don't need to go on the long, arduous task that is the search for Koudelka?