Actually this is completely unnecessary. I know the XAS demo sprites use huge charsets for all their sprites, but it will work just as well if the walking sprites are regular sized. I know this, because that Nethera attack sprite is an edited version of what I used for XAS, but the charset is the same. At least that's how it worked in 2.5, and I'm pretty sure he hasn't changed the graphic engine THAT much. try it both ways and see if it works.