Melffys are cute as fuck but dead serious when it comes to be a major annoyance for your opponent.
Runick Fountain and Melffy Hide-and-Seek makes for a great drawing / recycling engine.
Hugin the Runick Wings searches for Runick Fountain and can be used as a rk.2 xyz or synchro material.
The Runick engine combined with the melffy engine allows you to respond to each of your opponent's actionduring their turn. Melffy Wally can bring Melffy Catty and Melffy Puppy out. Then they can bring Melffy Pinny or Hop Ear Squadron to your hand and summon a beast to your field like Tri-Brigade Kitt, which can lead to the synchro summon of Merry Melffys or Desert Locusts, which can itself be used to summon Borreload Dragon or Baronne de Fleur, all of that during your opponent's turn! Melffy of the Forest and each of your Runick spells can further block your opponent and destroy their cards.
Tri-Brigade Shuraig the Ominous Omen works wonderfully with the melffy engine, allowing you to banish a card on the field (without targetting) each single turn as you summon out your smol creatures. Rescue Cat summons out Tri-Brigade Kitt and Melffy Pinny (or any other lv 2 beast), which can be used to summon Tri-Brigade Ferrijit the Barren Blossom. Tri-Brigade Kitt sends Tri-Brigade Nervall to the grave, which adds Tri-Brigade Kerass to your hand. Summon the bad boy, get another link2 monster out and then Shuraig can come out.
In a nutshell: this deck can go crazy! Try it!