44,000 damage Discoid and 0 elemental magic skill for JoL and Kirin (and most NMs I guess) were pretty fun also.
Pets not getting hit by AoE in Campaign was nice while it lasted. Immediately followed by pets getting aggro from everything in Campaign.
I'd say that this tops it all.
A bug occurred wherein Bards using March songs with Ryl. Spr. Horn +1 or Ryl. Spr. Horn +2 equipped would receive a massive boost in effectiveness.
Enough to make 2-handers swing like a 1-hander and a THF to swing like perma-Hundred Fists.
My /Bst bud had a nerdgasm when they briefly let pets receive samba effects, he figured it made too much sense to be an accident, and it was briefly awesome... then POW, back to normal.
I was about to level beastmaster when I found out that Djinns would explode if you casted a spell that matched the day's element, but they had to fix that too. >(
It was pretty sweet when they added Dread Spikes and Drain II and they were glitched out.
Having hasso or seigan up when casting made the recast like 7 seconds as long as you didn't have any haste gear on.
Perma-Invincible is win.
Until you get Fang Rushed, Rushing Drubbed, or something like that, or ran out of MP >_>
Remember when melees could disengage and reengage and their delay was reset so a 2h could seing as fast as a 1 hand but it was annoying to hit a disengage,/wait 1, /attack macro every few seconds for a 2 hour pt.
I had a blast levelling my lowbie RNG when they screwed up distances. You could stand out of range and blast worms forever because /ja and /ma (but not /ra) were accidentally shortened.
Though my favorite screwup was when they totally messed up the code on Reward. I think it was just Pet Food Delta, which would cure for like 12,000hp. Considering HP cured with reward is enmity towards the pet rather than yourself, it made for some serious tank-pets for the short time before it was fixed.
code can be convoluted and complicated w/o being unreadable and cause unpredictable repercussions. at my last job, i wrote some rather twisted computer vision code that looked like complete spaghetti logic, but because i commented the hell out of it, neither i nor my coworkers had any difficulty figuring out what was going on or how to change the code later. comments are your friend.
It's not just spaghetti code. When you use static memory reference, it's easy to fuck up something by altering something else. I've no idea how many hundred page of code they have after 6 years, but there is no possible way to keep a project like this "clean" if you were going for something optimized early in the development.