I can't speak to the merits of this as a gameplay mod at this point (unknown information can both work and also be a needless restriction in games of this style, and be something subjective in the middle -- is a memory test if it would count as one, or being forced to play defensively knowing the enemy could throw something unknown at you, necessarily a bad thing or even that unrealistic for want of a better term).
It is the sort of thing I have seen done in cheats, especially for more complicated games where the enemies might well almost be player characters in their own right and have all the requisite stats and limitations.
If you were doing it as a hack you would probably start by finding the enemy stats, or indeed possibly the player ones and then seeing if similar structures exist. Alternatively if you can find something like the enemy hp, mp or the like then chances are the other stats are near enough this. With stats usually sits equips and move lists.
Some flash carts have memory viewers, and if you are playing on an emulator then you can dump this data out (or indeed use Lua to make it into a nice table displayed on a secondary window/overlay if you want to go that far). The cheat thing comes in where people use the cheat engine to read data from one location and overwrite something irrelevant on screen with a reveal of the information (you may have to learn a key to know what single character/combo corresponds to an in game effect) or indeed overwrite in a further menu (who cares if system options is not allowing you to choose text speed).
If you are unfamiliar with cheats then
https://web.archive.org/web/20080309104350/http://etk.scener.org/?op=tutorial https://doc.kodewerx.org/hacking_nds.html
Lua
http://wiki.desmume.org/index.php?title=Faq#What_is_this_Lua_stuff_I_see.3F
https://fceux.com/web/help/LuaScripting.html
https://tasvideos.org/LuaScripting (often a subtly different take with some different function names but the principle carries)
Cheats are not very clean usually and Lua needs an emulator on the PC (don't think the phone options have it, some older machines might but it kind of is a PC affair for most things) so doing it for real tends to start off the same way in finding stats and presumably move lists with it. If you are a better hacker you will know how to do tracing (
https://www.romhacking.net/documents/361/ ) and thus can work backwards from enemy MP pools or your character's HP going down when hit by it in fairly short order. If the game has some kind of reveal spell/technique you can also attach a call to it (and possibly also lose any casting cost) to something banal that is always going to happen. Displaying data in game if there is not some nice info dump spell you can abuse for this faces many of the same problem as cheats above and you can go the same way of replacing data with something else, albeit with a bit more nuance owing to having more control of what changes. Otherwise you get to figure out how to cram more visual data into RAM and onto the screen (the finding graphics thing above while for the GBA carries over enough to the DS that it is what you have to handle,
http://www.coranac.com/tonc/text/toc.htm also good stuff if you want a more programming approach, naturally
http://problemkaputt.de/gbatek.htm having all manner of data on everything relevant in this).