#origamiblacksmith

[magicjudge]

How would locket of yesterday’s interact with Silas Renn? Would I be able to reduce a spell cast with his combat trigger?

No, this doesn’t work.

When you cast a spell from any zone, the first step is to move it from where it is to the stack. This happens long before you go to determine costs, and so Locket of Yesterdays won’t see that card in the graveyard anymore because it’s not there.