Weaponless enemies in Tempest Trials?

I had something similar happen; with Zelgius as well actually! I thought it was weird that he couldn't counter attack, but I didn't notice it until battle. Still, quite strange... maybe an error on IS's part? Maybe they forgot to have him equip his weapon?

It’s a glitch. If you look closely, he also has Luna equipped instead of Black Luna. It doesn’t only happen in TTs, but also in the training tower (sometimes he has random weapons there, he’s been seen with Brave Swords, Silver Swords and Zanbatos). It only happens to him though, so you won’t just randomly see a Nino without a tome

we better get 5 orbs because of this.

Same here i thought it was funny(looks like someone forgot there legendary weapon at home).