>>54322839Take a look at pic. Riddle refers to an event in Pokemon Masters.
Event had four Sync Pairs. Steven & Stoutland (Normal), Shauna & Klefki (Steel/Fairy), Zinnia & Thievul (Dark), Lyra & Phanphy (Ground)
>At a moonless nightZinnia is depicted with the moon behind her. No moon, no Zinnia. No Dark-type.
>Failed to get the keyShauna has a Klefki, which is obviously a key. No key, no Shauna. No Steel or Fairy types.
This leaves Normal and Ground. Though you could argue for no Normal-type since the Detective failed, but that's less strong than the other two.