Counterintuitive Interaction between Rubblebelt Rioters and Embercleave
I have Rubblebelt Rioters and several creatures and lands.
I am unable to pay the cost to cast Embercleave.
I attack with Rubblebelt Rioters and several creatures.
I am able to pay the cost to cast Embercleave.
The timing of the Rubblebelt Rioters "on attack" trigger coincides with the the cost reduction applied to Embercleave's cost.
The result is the Arena state processing resolves the Rubblebelt Rioters trigger, giving me no chance to cast Embercleave, even though the cost is now payable. This is blatantly counterintuitive. If I am in this situation, I am required to put the game into Full Control mode to cast Embercleave in response to the Rubblebelt Rioters trigger, which will optimize the damage.
I am asking for the Arena code to take into consideration that Embercleave can be cast for its reduced cost in response to any "on attack" triggers. The code just has to calculate that a card can be cast for a reduced cost caused by attacking creatures. The overlap here is clearly the issue.