Pokecreep

What's stopping you from gaining it?

The logic of shading the events is there, feel free to use that to accomplish what you want

There are plenty of examples of that, especially in this thing called Pokemon Essentials DS. It's not just a little thing to explain, you're asking to rewrite the way the entire game functions, which I won't even bother starting. If you don't have any prior coding knowledge, nothing I say would remotely help you anyway. Use the Kit if you don't know how to make it yourself, and reverse engineer it to edit it.