No. 4 - While Guthix Sleeps
When While Guthix Sleeps was first released, it was laughed off as a quest unworthy of being rated Grandmaster. It was largely believed to be "Grandmaster in name only", in that, as a quest already in RuneScape 3, it was not nearly as complex as some of the more modern Grandmaster quests in OSRS.
The overarching belief was that it was sort of thrown together using leftover source code, since it was backported from its original RuneScape release, where it remains one of the best quests in RuneScape 3 to this day, in 2008.
I'm glad I didn't do it the day it was released, because within a day, that changed. I was pleasantly surprised to the point where I almost had this quest all the way up at No. 3 on this list.
While the battle against the two Tormented Demons is still relatively straightforward, the real challenge is the fight against the Balance Elemental, which was buffed in pretty much every sense of the word after day one. The pace of the fight, which requires constant gear and prayer switches, is intense.
And don’t forget the fight against Surok Magis, which adds a nice touch not featured in RuneScape 3. Surok, too, was buffed after the first day, enhancing a fight that requires you to think fast and perform a number of actions not necessarily related to combat.
Surok’s three special attacks include summoning a warrior, which must be attacked with a specific spell, depending on which kind of warrior it is, before is reaches you, and throwing a lit explosive which needs to be telegrabbed and alchemised to avoid damage.
And of course, there’s the elemental surge attack. Whenever he casts between one and four of these attacks, they must each be countered by the opposite element. There’s a lot of strategy involved in this one, and despite not being the final boss fight of this quest, it’s one of the most fun individual quest fights in the game.