There have been some new game mechanics added with the Fabled set, the first being the introduction of the rotation system, which is refreshing the core constructed format by retiring the first four sets (The First Chapter, Rise of the Floodborn, Into The Inklands, and Ursulas Return) as of September 5th, when this set drops for all retail outlets
The optimal sequence of our commanders would be some ramp on turn 1 or 2, turn 3 Sophina, followed by Turn 4 Elmar, a second spell, and then swing
It's dealt simultaneously, and lingers between turns, so it's often not worth wasting valuable questing time on an even trade
The only expectation to this is if you can kill all your opponents (or your last one) in one go
Being able to be meaningful on 3 or 5 is huge for a ramp strategy