>>15910686In order to get the maximum out of both defenses (without curse), you could do 252 HP/148 DEF/108 SDEF (or 104 with 4 Attack/Speed at Lv. 50) with a +SDEF nature.
Or, if you assume +1 defense from curse, you can go a +SDEF nature with 252 HP/252 SDef and the 4 in either Attack, Defense, or Speed (though NOT in Defense @ Lv. 50)
