Elemental Stone of transcending the ash keys: ignore damage reduction (3 days) + 30% damage reduction through monster drops
Elemental Stone of transcending the ash keys: Ignore DEF (3 days) + 30% armor penetration monster drop

I was under the impression that one of those essentially ignores a % of the enemies armor, and the other ignore a % of the enemies dd.

All I know for sure is when people start socketing even more stats on to upgrades....HAHAHAHAHAHAHAHAHAHAHAHAHA.