B! Veronica IVs

Hello guys
I wanted to ask you
What's her best boon ATK or SPD?
And what's her best bane DEF or RES?
I want to merge my Veronicas so I want to know which one to take as base. Because a have a +ATK -DEF, +ATK -RES, and a +SPD -RES one.
I know that bane are going away soon so the most important thing is what's the best boon for her.