Well i just did it today and thought id would tell the world how. okay, so firstly, equip ed with an amulet if you have one. this will bring him back to life if he dies. also, give him the moon medal, its a good help if and when ed does die, replace his amulet (which will be gone) with a fullmetal ring if you have it. 100 extra hp can go a long way. then al, give al the double edged bangle, that way he can be of some use. give him the grindstone if you have it (but only if he has a sword) if he hasnt got a sword, just give him whatever else you want. alright, then move on to your items and use a magic capsule on both ed and al. if you dont have a magic capsule, i suggest you atleast use a defense one. now for bonus points. if you have any bonus points, put it into defense. i cant remember the number of times ive held on with only 3, 4, or 5 hp left. alright, now for the fight. by the way, do all this IMMEDIATELY when you gain control. after youre done this, move ed to the right and get al to tackle, and ed to dodge (R2) this way you can both avoid the stalagmites armstrong sends at you. alright, now immediately move over to the lightpost and create a tank thing. wait until mustang and armstrong get close to eachother, then shoot until youre empty. also, ALWAYS keep in mind that the tank CAN be destroyed, and if you EVER see mustang shooting some fire your way, or armstrong about to slam the ground in your direction, JUMP OFF. this way, you may take some damage but atleast the tank will survive. okay now how to deal with some of our enemies moves. when mustang shoots those fireball mine things that float around for about 100 damage, he puts his hand forward and the balls float from there. if youve got time (and hope you do) get al to tackle mustang. this way, he knocks down mustang temporarily and also detonates all the balls. dont worry though, al is invincible when he tackles. even if youre a little late, all but 2 or 3 should be gone. to get rid of these safely you can put a rockblock in front of them, or get al to guard in front of you and set them off. mustang occasionally also detonates all the bombs at once. he will say 'this is the end!' if you hear this, run. another move from mustang is where he shoots small fire balls at you from far away. they seem harmless at first, but upon impact they create a column of fire that send you flying. if all these get you a the same time, youre absolutely toast. the thing to do is to run a circle around him, that way each one will always miss. al might also be able to stop him from doing this move with a tackle, but i dont know. there is mustangs 'meteor' move, were a transmutation circle appears in front of him and he says 'this is the end' if youre quick, get al to tackle him and he will stop. if not, just run a little ways away from him. it wont follow you. then theres is mustangs casual 'stand back' move where he shoots a couple fire columns at you. you can dodge it by pressing R2 and getting outta there. thats it for mustangs moves i think. now on to armstrong. his first is this...corkskrew punching rock thing, where he punches a rock and sends 3 missiles flying at you for almost 100 damage. simple rock blockers can stop that. then theres his normal combo, which can be avoided by running small cirlces around him, afetr dodging his 2 or 3 hit combo, unleash your own combo. then there is his 'strut' where he flexes his muscles and if you try to attack, he knocks you to the ground for 300-400 damage. just leave him be when he flexes. then there is his super rock punching move when he says 'this is alchemy at its finest!' where he punches a boulder into a dozen or so missiles. this is easy to dodge if al is in front of armstrong, and youre behind him attacking. finally, there is his super combo, where he punches the ground at first. this is stage one, where he paralyzes you. if you use a relax herb quickly, you can get out of there easily. if not, he hits you like crazy for 100 damage each time, finishing with this crazy super punch that sends you flying. just use a relax herb quickly and jump out of the way. you can attack him from  behind while he finishes his combo. then there is his stalagmite move, which can be rather annoying. a quick R2 to the side will save you. that covers armstrongs moves.

now into the actual strategy. i say you take out armstrong first this way you can give al the demon fist that he drops, and possibly beat mustang in one punch. (maybe) what i did, was from the start put all my points into attack. with this, i was doing 80 damage to begin with against armstrong. he has 9999 health, so you can imagine hes pretty tough. the key though is patience. when he does his 2 or 3 hit combo, run circles around him. when hes done, do a combo of your own. youll only get 2 or 3 hits in at a time, so be patient and DONT try to make things hasty. after hes gone, youll get 9999 experience points. then onto the colonel, who is very hard to hit. i got the tanks to attack him for a while. then, i kept al close to me and kept getting him to tackle mustang. this way, hes in the air, and i can perform a combo on him with ed. CONTINUE doing this, it takes a long time, but it works.

and keep these few rules in mind:
1) no mater HOW small of an amount of health you lose, ALWAYS heal right away. dont be shy to use all your elixers, this is your last battle.
2) NEVER heal al, unless using a doubalixer. if al dies, you walk over and transmute him. if ed dies, you lose. no brainer
3)BE CAREFUL with your tanks, they are valuable, and will be destroyed if youre not careful.
4) slow and steady wins the race, follow this guide and you should be ok. for any extra help email me at [email protected]