In this mode you start with power instead of cash and unlike other modes you cannot gain power you only lose it. Placement costs do not apply here but each unit rarity has a power usage. Higher rarity units use more power lower rarity units use less so you need to use mostly lower rarity units.

Enemies are not very strong here so bringing too many units wastes power because each placed unit uses power. It is important to know that only placed units consume power. This is a key part of the meta.

Each map has three key spots where enemies from their area funnel through. You must have at least three units placed at these spots at all times to stop them.

Upgrading units also costs power so managing your power carefully is important. The amount of power you have left at the end decides the quality of your rewards less power means worse rewards.