Question about GW

Is it allowed to change the guild leader right before the Guild War starts? In a server that I played, it wasn't allowed... how about here?

It happened a while ago when I started a war against another guild and I killed their "leader" in the second the war started. I saw their leader dead on the ground, confirming that he/she was dead... but the war wasn't over until someone asaled me and I died. I got mad of course, and I was asking them if they changed the lead or not (ofc they did but I was looking for a confirmation)... some of them said they didn't... some of they said that it was allowed and there's no problem on doing so... anyway... I'm not butt-hurt, it's okay if I lost that battle but that wasn't fair in my opinion.

Yeah, It is allowed to change leaders before a Guild War begins, they transfer it to an alt char and just make it fly so it can't be touched or killed and so that they can have a nice long guild war that might lead to a truce, surrender or just let the time run out and see if who wins.