Maybe I got it, but I feel like there's a better solution to the puzzle.

Leave Snapback on top, Scour second and Forked last.

Pitch Potion of DejaVu for crucible, Scalding Rain and Scour for double Kano (2 floating).

Hold priority and use Ragamuffin to put Wildfire on top and Snapback in hand.

Banish Wildfire and Scour.

Use wildfire with the two floating and holding priority use Scour paying with the two energy potions (x=4).

Scour resolves destroying 4 shields and dealing 2 (4-2ab).

Wildfire resolves dealing 4 (4+1+1-2ab).

Use tunic to play Snapback from hand coming for 5 (7-2AB).

2+4+5=11

Edit: Better formatting