The Temporal Beacon card increases the movement and attack speed of all units within its radius, and the effect can be stacked, enabling you to get through a particular area of the loop faster. The card can also spawn a powerful enemy called a Watcher on the tiles within its radius which can cause problems so the decision to use this card must be made carefully. You can however stop the Watcher from spawning by building a Vampire Mansion nearby.
How to get the Temporal Beacon Card
In order to get the Temporal Beacon card you need to complete 13 loops in a single game which is not easy to do and will require some careful planning as the enemies get stronger with each loop. You will need to use cards that improve health, and healing, while putting down just enough cards to generate monsters that will provide loot without filling the boss meter. Before you attempt the run you should also make sure that your gear is up to it, and you are able to keep up with the increasing enemy strength each round.
It is therefore recommended that you attempt this in Chapter 1 which is the easiest chapter in the game and limit the number of cards you put down on the loop to ensure you do not summon a boss which could quickly end your attempt to get 13 loops in a single game. A good card to place is Spider Eggs as it generates a lot of monsters and will give you the best chance of surviving the run and also getting good loot at the same time. Another good card to place is Chrono Cyrstals beside Meadows so that you double up your healing effects and get more health each day. Although not easy to get the Temporal Beacon is worthwhile having as the options it gives you will help you considerably in the late game.
Check out our How to Get the Maze of Memories Card, so you can summon the boss early before it has had a chance to build up its power.