- Sword of Mana (GBA)
I great idea for a hack would to be to circumvent the Amigos System in Sword of Mana on Gameboy Advance so you can complete all the quests in the game. As is, you cannot complete quest 41 as it requires showing an Chekov a summon card only acquirable via registering friend to your game. Perhaps even a hack that marks the quest completed.
I managed to circumvent that that system in Sword of Mana on Game Boy Advance not using ROM hacks but by using cheat codes to obtain everything in the game including the summon card in question. I will just offer advice on what to do to get the summon cards, I cheated for plenty of other things in the game but since that is all you are interested in I will limit things to that.
First you need to turn on a GameShark “Master Code”, for the code giving you all cards to work:
Next, here is the actual GameShark code that gives you all cards in the game:
Put all those codes in your emulator and you will have all the cards. Then just show each of the 7 summon cards to Chekov and you can REALLY complete quest 41 (he only needs to see one to “clear” the quest but he will keep going for all 7).
Another much more tedious method that can be done in emulators is basically described here: https://mana.wikia.com/wiki/Seven_Wisdoms
That describes how to do it using two Game Boy Advance systems connected with a link cable. But it can also be done with an emulator able to emulate two GBAs running at once that are connected by a link cable. mGBA, NO$GBA, VBA-M, and VBALink can all do that. VBALink is slightly more advanced in the linking emulation because it can emulate a link cable over a network, while the others can only do it on the same computer. I think VBALink might also support emulation of the GBA wireless adapter but I am not sure. Anyway since Sword of Mana just uses the link cable and not wireless card for GBA, there is much better support for it in emulators if you want to use the long, tedious method. A method that does not involve any cheating or hacks at all, but is annoyingly time-consuming to get up to 100 Amigos in order to get all the summon cards.
Yeah so, I prefer just using cheat codes. Much easier! Anyway I am just giving you these workarounds because although it would be nice to have a workaround to the Amigos system via a ROM hack, you can immediately use either of these solutions (cheat codes or emulating a link cable). One of which is easy and gives you all of the summon cards immediately, the other of which is annoying and takes too long. Still if you refuse to cheat and want to do everything 100% legitimately you can try the more tedious method I outlined. I think that is silly though, much better to just put in the cheat codes, get all your summon cards, and be done with it.