I've complained lots about FF4A, particularly regarding how the trials suck... mostly regarding the story (because, they aren't really that great, outside of say Kain).
However, I remember one trial that is shockingly the worst above all else (feel free to disagree).
Edward's Trial is built poorly on a faulty premise... Edward may suck, but the game gives you all the tools to make his life a living hell.
1) Requirem Harp - Why put in a weapon only to be removed? It could arguably be a great weapon (better than the Blood Lance and Blood Sword).. assuming they got it working correctly the first time around. However, the mistake in doing this in the first place causes Edward to lose the weapon before the boss battle... IIRC. I guess it could be worse.... the designated special weapon for Edward, Apollo's Harp, is a very capable weapon vs Lunar Shiva... so this mistake can cost you when you are using Edward to fight...
2) Low HP - Edward has approximately the same HP growth as Rydia... and that's only slightly above the twins (Porom being the worst of the final party members, Tellah and FuSoYa trailing horribly). Considering that the boss, Lunar Shiva uses an attack that is primarily HP based (based on her current HP), this makes survival tough... except for the fact...
3) Red Armor set (FF6-ish armor) - It's great when armor provides elemental resistance. It's hard to argue against it. However, FF4 has been designed around elemental weakness in armor... and causes "fire resistance" to also create "ice weakness". Factor in that the boss is Lunar Shiva... well, you give the keys to killing Edward in one easy blow. Vishnu Vest is Edward's ultimate armor, however IIRC this is only acquired AFTER Edward's Trial location. This would normally addressed the Red Armor set's woes.. but most newbies won't figure that out. Maybe donating a Protect Ring would be helpful... probably. The other options are a freed up Black Belt and/or the DarkHood...
Now if only the Chant command weren't useless against Zeromus...