So this happened a while ago, I made a ticket about this on the 21st of Oct when this happened. I have been asked to report the issue here.

I was doing my daily battle quests as per normal. I was asked to defeat Mephysto at level 7 on my battle quests so I went ahead and challenged him. I finally eventually beat him, after a few losses and returned to the battle quest page and I was still being asked to defeat him (also still says I am on level 7). I thought I'd try and defeat him again to see if it would work and I would receive my reward for defeating him, however this was not the case and I am still on level 7 being asked to defeat Mephysto and definitely do not have any reward from the Battle Quest.

I have tried refreshing, exiting my browser and reloading it and returning to the battle quest page. I am using Google Chrome on windows 10 and have never had this problem before with other challenges (though this is the first time I have been able to defeat Mephysto, so perhaps it may be a bug with that?)

I battled him with all attempts through the quest page. My pet Jadora did not appear in battle with him when I checked the statistics page. I was not stuck on the quest, as I could skip (however I had no skips remaining) and when the server hit midnight my quests reset and I was able to do my BQ as normal.

Any insight into this would be much appreciated. I am not looking for anything from this, I just don't want this happening to anyone else :)