(Spoiler, is there an actual spoiler tag?) You have to use a charged attack with a single handed weapon to complete this quest (maybe a spear also works, but I know a two handed weapon doesn’t).
Besides just leaving this information here, I also wanted to mention this is some bullshit.
Same here, after a while I just thought to myself “this has to be it, I’m probably missing something” and checked online to find out it was a charged attack for some reason (I guess because it hits all of them at once? I don’t know)
And yea I think you get a cool sword in the end but other than that these ruins seem kinda pointless