Eversing

The Eversing is one of the toughest armors in the game and was tempered underneath a waterfall for many milleniums.

In Castlevania: Aria of Sorrow, it is the highest item that only provides a Defense boost (+45). This is greater than the Gold Plate (+38), but less than Demon's Mail (+49 and +9 STR and ATT with protection against the Dark element).

In Castlevania: Dawn of Sorrow, it is again the second highest DEF item in the game (+46), which is greater than a Cuirass (+38) and less than Demon's Mail (+55).