Haven

Strategy and Synergy
When cast, Haven will give 60 shield points to every Being on the playfield and the player. There are very few instances where this will hamper the progression, specially later on the run where the player is highly likely to attain several powerful spells and artifacts. Coupled with its free cost makes Haven a worthwile spell to consider, specially towards the middle of the run onwards.

Without any upgrades, Haven is pretty straightfoward as the shield bestowed upon the enemies can be easily taken down, but be careful if you consider applying a few upgrades such as and, as those will increase the shield attained by the opponent even further. Those two upgrades are better reserved for and  instead.

The upgrade will turn Haven into a secondary, which is useful when there are ways to work with  stacks, such as when playing with Doubletime Violette.