It appears that the WooHoo system is only available to the Tiefling class, but the Tiefling class requires 5 WooHoo interactions to unlock, meaning I am stuck with the vanilla gameplay. If there is a way to perform the WooHoo system as classes other than Tiefling, please let me know because I've tried mashing all the buttons, and I seriously have no clue how to. Otherwise, from the screenshots, I speculate that the Amulet of Desire is the sole method of the WooHoo event.
Not exactly. The Tifling class's features are built around the WooHoo system, but WooHoo is available to all hero classes.
1. WooHoo can be used on any sleeping enemy (except bosses) from a distance of 1 tile.
2. There is a WooHoo potion that can be used not only on enemies.
3. You can find a magic wand that applies the WooHoo effect.
4. You can find an enchantment for weapons.