Sustain

Description
Gain 1 Trinity, if Trinity is full, gain Shield equal to the damage of the spell in your other spell slot if you have one.

Strategy and Synergy
It works well with the same spells can synergize with, like. It is a bit weak for a legendary spell, since it needs setup and deck management for its effect to work.

However, in a dedicated deck, Sustain can be quite powerful, and can be used alongside staple spells like  to repeatedly generate 60-120 shield throughout the battle. This can make your Trinity deck much more flexible when choosing which spells to use your Trinity Casts on, but take care not to waste it on a spell with low base damage like.