How can we be DoT Mages with no DoTs?

[Eloah]

20% of Bane is 126 potency, which is more than 50% of Holy which is 100. That's not counting the 250 potency of Shadowflare.

There is a difference in that you can't spam it though.

Now that is the 20% potency, NOW, when we lose our 3rd DoT that 20% will be lower. And also as you indicated it cannot be spammed. These are DoTs if they don't tick for the full amount of time they lose potency, which makes it worse. And for right now Shadow Flare is one of Our DoTs, but it will not be once SB is released.