Help with new item png image files

[Fatt_Shade]

I already edited item to add 2 more lvls in items.txt file in my sessions/mod folder. First upgrade i copy from runic sword just replaced units that apear in battle, and for 2 upgrade used archmage staff strings also replacing nuits that apear. In first unupgraded version of item added :
params { upgrade=battle_axe(2nd),war_axe(3rd),executioner_a xe(5th lvl) } ,
and text in item in game is ok, but i cant upgrade it since i have no new image for upgraded item, and after battle with item guardians i get next lvl with no picture and it doesnt work ((
As far as i can tell editor is for visual aperance of something in game, mechanic of game is in .lng .txt .atom files in mod folder where game is instaled. So far my editor is horrible with chrashes and i cant work in it at all.