A group of people from Arthurian times, including king Arthur himself find themselves in another world/land and they must rebuild a city after a war (??) has ravaged the lands? (Yay portals) Then there is a time jump and the main character lives in this city and is on a quest, with friends. He refuses to use a sword so wields a quarterstaff always. There is some sort of soul bond on a sword. But elves have made a sword that only he can carry: the sun sword (or similar). Plus there are giant telekinetic (?) spiders or something. And ice men! They are trying to fight and main dude needs the sword to kill them. There are also corrupt nobles.
Think of every trope in fantasy and add it to this series and you'll know what we are trying to find.
There is 4 or 5 books in the series. They were read last about 4 years ago, so nothing new. It's definitely not Game of Thrones.
I know this is vague as heck but trying to help a friend who read the first 4 books 4 or 5 years and wanted to read the 5th that hadn't at the time even written yet.