good guides for modding custom abilities + items, documentation?

[toasterbathbomb]

im interested in getting more into the technical aspect of creating custom characters (special abilities and items, custom animations, custom pets, etc) but i'm having trouble finding up to date guides/tutorials and i've had zero luck finding any documentation. other than whats in the pinned threads, does anyone have anything that could be of any help?

thank you!

[Monti18]

Did you have a look at Ultroman's Tutorial Collection?

There are quite a lot of guides in the subsection of this forum, it's at the top named Guides and Tutorials. Normally these are enough to get a starting point.