Both players are playing cards from their opening hands, and establishing themselves as the aggressor or the control player
It is likely that we will see a counter spell soon (we play 6 of them in the sample list above), and by the time creatures become a major issue, two white sources will probably have been drawn to fire off our Wrath of God
Lets add a bit more happiness to the world, one card at a time
You pay two mana this turn, you get a two-mana payoff on a later turn
Your ideal sequence on turn one is land, pitch a Black card to Grief, place the incarnation's death trigger on the stack, place its discard trigger above it so it resolves first, and remove your opponent's interaction if any so the way is clear for you to target your incarnation with Ephemerate
Though rare, reusable copying effects like Cloven Casting, Bonus Round and Reiterate are massive force multipliers to the point of becoming win conditions in their own right