The Arena is a ring for beasts to battle against one another at the behest of a Beastmaster - while within the ring, they will greatly improve their combat efficiency at a quick rate.
As the two heroes are deposited in an unceremonious heap inside the bloodstained pit, a sadistic roar of pleasure raises a small cloud of dust, painted with the gold light of the torches it casts a gilded veneer over this opera of death.
A monstrous beast carrying a whip strides to the head of the Arena, behind him circle two frothing fiends that nip at the air while they eye their next meal. With a crack of the whip they burst from the sidelines and charge the heroes to a homicidal roar of delight that drowns out the tortured screams of these two ex-prisoners.
If there is a greater pleasure than the observation of suffering in others we have yet to find it. Various double-blind studies have been conducted and all have concluded that minions who observe the bloodsport of the Arena are six times more likely to be retained until, and sometimes after, death. When you are busy entertaining yourself elsewhere your Beastmasters will quickly rush to this room to pit your Beasts against one another in non-lethal combat, granting them experience to make them even more deadly in whatever future battles may unfold.
Refrence : https://wftogame.com/wfto-wednesday-82/