Probably a more unusual Mild (+Special Attack / -Defense) or Rash (+Special Attack / -Special Defense).
Reasoning: Should have enough Speed without boosting it to move first. Would not want to drop it, however. Lacks great defenses. Prefers to bolster its offenses, which are not overwhelming.
Has a slightly higher Special Attack than Attack. Leans into that, consequently. Learns some good Special moves, including Surf. Wants to use Greninja's Dark typing too, however. Picks up only one special-based Dark move. Comes from a TM that is only accessible after getting all 8 badges. Means relying on physical Dark moves.