Temple of Focus is an epic structure that commands friendly units forward at the start of your turn. Upgrading it will increase its strength. Temple of Focus can be used in decks needing more movement.
Temple of Focus essentially commands forward all friendly units in front of it. This causes the units to move an extra tile at the start of your turn.
With Temple of Focus, you can place a unit two tiles away from the enemy base and still have it attack the enemy base.
You can also use Temple of Focus's ability to simply gain more frontline on your turn.
Temple of Focus can also remove the confusion status effect from your units, ensuring that they go forward when commanded.
The damage Temple of Focus takes is relatively negligable as its effect triggering will provide you with an advantage already.