Here is my strategy for defeating the Fire Guardians. I used fireballs as my weapon, though other spells might work.
You want to stay on the lower platforms as much as possible, jumping between the two as necessary. Try to always be on the platform nearer to the Guardian that just fired, but away from him as much as possible, ie. toward the center of the screen so you can see both of the Guardians faces. Turn to face the further Guardian, the one most likely to fire next. When he fires, jump up toward him and over the fireball -- you should have enough time to plan your trajectory, inching right or left first to make sure you can clear it. If you dont land on the platform nearer to the Guardian that just fired, then get there ASAP. Again, inch away from the nearer Guardian and turn and face the further one.
If it looks like the nearer one is going to fire first, then jump to the other platform, turn, and be prepared to jump back over the fireball; or if he fires at your back while youre jumping, the fireball will head upwards above you as youre descending from your jump -- a duck may be required rather than another jump.
Occasionally a fireball will come in from above you or both Guardians will fire at the same time, and then youll have to scramble. But for the most part, with this strategy the fireballs will come in at angles low enough to jump over them and/or with enough time for you to figure out how to avoid them. It also positions you so youre usually able get good shots at the Guardians when theyre vulnerable. When one of them shows the signs of being vulnerable, jump up -- and toward him if its the further one -- and shoot two or three fireballs at him.
Hopefully this will work for you, tho' it might take a bit of practice. I have actually defeated them while taking as few as two hits using this strategy -- no need to waste a res necklace or escape ring on this level. Good luck.
LT
