How much of the normal process of doing alchemy can be circumvented by seeing Truth? I saw someone on the internet wonder if Ed and Al are capable of doing flame alchemy because they have seen Truth. This bothered me, since this would negate the idea that flame alchemy was difficult to learn and that via destroying Hawkeye's tattoo, it would be possible to avert the existence of another flame alchemist (vol. 14).

Someone suggested that it's possible from an omake where Ed finds Roy's lost gloves, puts them on, and creates an explosion. (Click to see images.)

However, this is an omake so I doubt it can be taken completely seriously, and moreover, Ed does not seem to have any of the technique Roy has honed. Yet at least with flame alchemy, where manipulation of gas concentrations is necessary (vol. 1), technique and precision seem to be crucial. Given this, I would normally expect to be what Ed describes as a "rebound".

Does seeing truth indeed allow alchemists to circumvent the normal learning process, provided that they at least have a rough idea of what materials are involved and the arrays needed, if they are lacking in the specific techniques that would normally be indicated by the ability to use an array? (The latter bit is necessary; otherwise, there's no reason why Ed and Al don't learn for three years how the philosopher's stone is created.)

Of the four alchemists who have seen Truth in FMA, all of them seem to only have gained the ability to perform alchemy without an array, and if I'm not mistaken, we only ever see them perform transmutations that they can be presumed to have already known beforehand. We do see Ed use Scar's deconstruction technique once, but unlike with flame alchemy, there's no question of needing the correct combination of materials or precise "technique" here.

I am looking for answers based on the manga.
From my understanding, all that seeing Truth does is allow one to create an Alchemy Array with their own body (as opposed to drawing it). it should be noted that in the 2003 Anime1 that even though Ed could have been doing circle free Alchemy from the moment after he and Al tried to being their mother back he still used circles. his first discovery that he didn't need them was when Gracia was giving birth and his second attempt was during the State Alchemist Exams

Mustang knows all the finer details of his alchemy because he had to learn it all from himself just from the Tattoo Riza has on her back which was placed there by her father, and further simplified it to be a smaller circle


  Flame Alchemy is the brainchild of the master alchemist Berthold Hawkeye, who had spent several years perfecting it before his death from illness in 1905. Believing it to be the greatest and most powerful form of alchemy possible, Hawkeye refused to pass on the knowledge to Roy, who was his apprentice at the time, and instead entrusted the secrets of his search for knowledge to his young daughter Riza - tattooing the perfected array onto her back as the only physical record of its existence. The full array appears to consist of a circle corralling an inverted hexagram made up of a large air triangle and a large earth triangle, both splitting into identical pairs as they intersect, with a fire triangle at the center, pointing upward toward a flame. Below the hexagram is an image of a salamander. Outside the circle is a pair of entwined basilisks and the text of the "Libera Me" responsory repeated multiple times. After Roy gains Riza's trust and takes the Flame Alchemy knowledge for himself, he modifies the symbol somewhat for his gloves (removing the text and the basilisks in favor of a simplified circle). 


Source: Roy Mustang - Flame Alchemy (4th Paragraph)

while the Omake being canon can be questioned, logically Ed could just as well do the exact same with Mustang's gloves as they are a simplified form but he wont have the finer control that Mustang has and will most like just cause very big explosions...or blow himself up.

Outside from using the gloves, Ed would still need to know the kind of Array to use to subconsciously alter his internal array and the procedure needed to utilize it. as for understanding the Array Ed has demonstrated in Lab 5 that he is quite knowledgeable (understanding the one to create the philosophers stone and altering it to be more efficient) which one can assume the ability to understand array's he's never seen before comes from the knowledge he gained from The Gate and Truth (as knowledge on Homunculi would have came from books he already read, after learning about Winry's parents Ed says he read about them in a book), as such looking at Berthold Hawkeye's array he may in fact be able to understand it quicker than Mustang. though at it's current state with the important aspects for it having been destroyed by Riza's request Ed would probably need to study in order to figure out what is needed to complete it



1: Brotherhood skips a lot of Ed's early years but i do remember events from the 2003 anime being the same as the manga (ie, Bald, Nina being chimeratized and killed by Scar, Barry the Chopper) so it stand to reason that up until Yuswel it is more or less the same