Skelly will work on undead/fiend levels except fire themes (wont be useful at fsc), those monsters still do half normal damage (on at least one of their attacks, cant tell if all), so the uv is great, only contender to normal here is fire resist. So, keep it if you want a shadow armor because from a quick look the sum of its defenses is better than the sum of normal+shadow of other shadow armors. A shadow armor is not necessary (you can play with any armor you like if you don't get hit and you dont lag, ever :P) but will increase your survivability a bit on the levels where it applies.
Skelly will work on undead/fiend levels except fire themes (wont be useful at fsc), those monsters still do half normal damage (on at least one of their attacks, cant tell if all), so the uv is great, only contender to normal here is fire resist. So, keep it if you want a shadow armor because from a quick look the sum of its defenses is better than the sum of normal+shadow of other shadow armors. A shadow armor is not necessary (you can play with any armor you like if you don't get hit and you dont lag, ever :P) but will increase your survivability a bit on the levels where it applies.