Defeated the Bathysmal Vishaps! Wait... They Got Back Up Again?

Hello, Travelers~
"The Call of Ice and Thunder" challenge of the "Three Realms Gateway Offering" event has begun. Complete the "Three Realms Gateway Offering: Aftermath" quest to begin the challenge.
In this challenge, you will face even more powerful Bathysmal Vishap elites. Is there a way to fight them successfully with ease? Let's take a look~

While fighting, the darkness in the field will condense. You can use the Bokuso Box to dispel the darkness on the field and prevent the Bathysmal Vishaps from going into a berserk state.

Stand in the Sentou area to continuously replenish Bokuso Box energy.

If a Bathysmal Vishap leaps onto a wall, destroying that wall can cause it to enter a weakened state.

After defeating one of the Vishaps, you must defeat the remaining opponents quickly, otherwise it will revive.