Just for anyone not aware yet, the Nintendo WFC, which was shut down in 2014, is accessible WITHOUT USING ANY HACKS in generation 4 and 5 pokemon games (other games as well) using Wiimmfi and other custom servers.
Here is the tutorial on how to connect: Video Tutorial
Here is the invite link to the Pokemon Generations 4 & 5 Custom Wi-fi Servers discord: Discord Server Invite