Diamondskin is supposed to provide 3 turns of protection? It seems to only provide 3 blows of protection.
Backswing either gets around or neutralizes it somehow- diamondskin should provide immunity from backswings.
Was this for fallen Enctness game? it's should keep you safe for 3 turn from melee or arrow, but not sure about magic damage... 3 turn based on one who use it, not enemies's turn...
You better report in support in that game, rather than here...