So you want the ability to save other player's character?
well basically my character
Ok
But if you or anybody finds a way please let me know...
I havn't heard about some client have that ability. It is not difficult, but useless: why don't they use some local inventory editor to create a player like that?
Internet lagging may cause server side character overwrite local player, but it is not a good solution i think.
You know you could just spawn in the items on that character for another character instead of waiting for someone to make a hack for it.
Its much more simple.
As i remember YATC 0.3v has this option. Join the server and .invsave <name> Then just go to single player and do .invload <previous name>
You could also just spawn the items in but that is much slower