To what extent is it possible to manipulate game's visuals from client side?

[Extor Prime]

I know we can replace some textures (icons, maps) in the client. Is it also possible to manipulate power visuals?

 

For example, can I make a fire bolt look like an energy bolt by replacing the corresponding textures and/or models? I know that only I would be able to see the client-side change, and that is all that matters to me. If this is possible, where do I start?

[KnightSoul]

This is a link to all the archived guides on the subject matter.

 

I don't see any reason it shouldn't be possible, but it would be far, far more complex than a sound file swap.  But I'm just a guy with a link, so read up until and expert spawns in.