Here's how it works, with Rika's Claw and Sil'fer, will give you pretty much an A rank every time:

Set Dice to 6/6, Deck: Unshuflled, lvl: Nebula 2 (iirc, anyone where Reiz starts 5 blocks away, and can run forward 3, and be one away from you)

Turn 1: Dice+1 on you, Dice+1 on Reiz, Mag x2.

Turn 2: Rika's Claw, Exchange, 1 step forward, HP Attack+Double Attack.

Sil'fer base AP is 3, +2 mags = 5. HP Attack = 18 dmg, x2 (Double Attack) = 23 damage x 2 = 46 damage, minus -6 (Reiz uses a Wall card, which subtracts 3 from the 23, making it 20x2)