Trust me when I say, its not as easy as you might think, making a large scale game in flash is a seriously difficult task, for even the most seasoned flash user, I can say this from personal experience. You have to take a lot of factors into account.
1) How much free time do you have, cus making a pokemon game in flash/photoshop takes forever, it can take a day or so just to make one map.
2) How well do you think you can pick Flash actionscript up, its not the hardest language to learn but once you get into the more complex stuff it can be difficult.
3) How many people will be working on this, cus trust me when I say one person would take years and years to make a game like this in flash, so defiantly get a full team to help you.
4) How big will the game be. You have to remember that everyone playing this game might not have a good computer, as such a game the size and complexity of a pokemon game, could take hours to load for someone with a slow connection or slow computer. As such loading screens every now and then will have to be an option.
Im not trying to put you off or anything im just saying, its not a small task, and you will need help, a lot of time and a lot of commitment, but if you think you can do it, then I wish you the best of luck with it.
