how long did it take you to develop adequate downpicking muscle power for master of puppets and tornado of souls, and how long had you been playing when you were able to play a killer solo like the one in tornado of souls
Downpicking is more about coordination than muscle power - you can tremolo pick at insane speeds, but you won't be able to downpick at the same speed because you'll lack the coordination. Keep practicing your picking and it'll come, eventually.

Any solos can be learned, provided they don't go much faster than you're able to pick at max speed (without losing control). Megadeth solos have a lot of speed in them, so I've never really had my eyes on them, not to mention the fact that Dave Mustaine streches his hand like a madman, far more than I'm capable of. "Crazy" solos like that are impossible to learn until you have the left- and right-hand speed down, and if you're not able to make the streches, you're going to have severe problems as well.
I'm a communist. Really.
I f@#ed my arm up big time from playing master of puppets over and over. I stopped playing it with down strokes and learned to play it with alternant picking. It can be done.
well, i am doing speed drills and scale drills along with learning the solos and getting better at it, but i'd really like to know how long a person who can play the entire solo of tornado of souls or something similar, had been playing and how much practice he'd put in.
I know someone who can play the ending solos of Hangar 18, alot like tornado of souls. He has played for 5 years.
it's all about patience, don't try to play what you can't, it only pisses you off, trust me i know