Notes from author
This build focuses on using the Catalyst and castings as its primary means of attack. Because of the ease of dodging most soul arrows, it can be extremely difficult to use.
The standard Great Soul arrow has a respectable damage when it connects. In reality the spell is to keep pressure on a target, keeping him rolling and dodging, and away from you.
Quickly switching to great heavy soul arrow may throw off their dodge timing and result in an extremely powerful hit. Not many people expect to see this spell, and though it doesn't mean it'll always throw them off, it does grant the spell some use beyond normal spamming. It also possess extreme stagger capabilities.
Crystal Soulmass can be a devastating contributor to damage. So much so that I kinda feel guilty when every one connects. Try cast it unlocked and pointed away from the enemy and then maneuvering it to hit. Rolling towards your opponent, or spinning them around is a great way to surprise them. Get creative with the cast.
The next two slots are completely optional. Removing a cast of either soul arrows may free up another. I would recommend taking a single iteration of Crystal Soul Spear or Dark Bead for healing hosts, or two for gankers. (Quick switching to TCC and Bellowcrest ring can turn this build into a ganker's nightmare.) Other casts such as White Dragon's Breath may find use, however one may wish to pull some points away from Int if they have no desire to use it.
Karmic Justice can be used to great effect, however it is very situational, Replenishment may be a better alternative when combined with Sanctus. Tranquil Walk can also be used to allow your spells to connect. (If you use with Dark Bead or Souls Spear, you're an ass.)
Playing this build highlights the weaknesses of sorceries. Expect to miss, A LOT. But it strays from most sorcery builds which rely on the sheer power of casts like Dark Bead, and ends up being gratifying to use.