Deoxys is a really bad choice for NatDex AG. It's outclassed by Calyrex-S, the premium Psychic-type in the tier. If you anyways want to run Deoxys, a mixed set is best for it. Superpower + Psycho Boost can punch through most bulky balances and offences, especially if running Focus Sash but is usually downed by Marshadow and/or Arceus long-term.