you see, i also thought relaxed suicune was useless, but then it kinda struck me, if your going for +Defense nature, most natures are alright, except those that -Sp.Atk or -Sp.Def, so i was thinking this;
Suicune @ Leftovers
~Aqua Ring
~Hp Electric
~Surf
~Calm Mind
you use Aqua ring alongside leftovers to get 2/16 HP a turn, this can make it easier to stay alive to set up a calm mind or two, then, you are Specially Defensive, gaining more HP, and Physically Defensive, so the now you use HP Electric and surf to attack since you have more special attack,