Well, good to know what awaits--

Wait. Destroy?
So I take it those seeds are VERY required for that... guess I'm gonna have my work cut out for me!

Current growth: 82.

Speaking of seeds, go and fight Raging King Destroy, he drops Dark Seeds which makes it easier to complete the Destroy sidequest. Doing so unlocks the Despair Door, where Destroy awaits. Aside from that, your entire party should be Lv: 99 in order for you to stand a chance.

Also don't forget: Once you get Destroy down to half his final HP meter, he'll start taking 1 damage from everything. In other words, you'll need attacks that deal 999 damage and a way to regenerate MP.