Controlling Robin's neutral attack combo: Arcfire or Elwind

In the third strike of Robin's neutral attack, it is either a fire attack that uses up Arcfire charges, or a wind flurry attack that uses Elwind charges.

Given that there are sufficient charges of both tomes, is the outcome of the third strike random? I've been trying to choose one over the other consistently by testing with simultaneous directional inputs but I can't seem to control when I get Arcfire and when I get Elwind. How can I control the output?

Solution 1:

Elwind is Robin's Rapid Jab¹, while Arcfire is the regular Jab. For more on Jabs, see the Smash Wiki.

To initiate a character's Rapid Jab in Ultimate, while both sticks are in the neutral position, quickly and continuously press your attack button (which I'll assume is A) until the Rapid Jab starts and then hold A to continue the hits, letting go to release the final hit of the Rapid Jab.

To do a regular Jab, press A once for each hit or hold A for all of the hits.

^{1. Fun Fact: The Japanese version of Rapid Jab, 百裂攻撃, directly translates to "Hundred Rending Attack."}