Notes & Combos
I stole a Runick Spright list from here and added Melffy cards to it. The Melffy line mainly comes in clutch vs Shifter. Runick + Normal = Gigantic, gigantic to blue to jet, overlay those 2 for Melffy of the Forest. The negate on the XYZ is actually very impactful vs Kash, the best deck that runs Shifter right now (and it's also good vs floo lol). Then you get a Synchro 4 and the backrow from Jet which can shut down a turn for sure. Next turn once Shifter is gone it's trivial to get back into the standard Elf/Runick lines from there.
3rd Hugin is probably optimal, cutting the Melffy Synchro or even Avramax could be the play to fit that in. Things fall apart without 2nd Elf/Gigantic, they're critical for grind games which is the only kind of game this deck plays. Sprind synergizes well with the Melffy cards but it's tough to fit that in the endboard when it doesn't summon anything off the mill.