This could work really well in location focused decks, giving you ample power to challenge other locations or characters and stay on top of the pace of play
Morophon is a seven mana colorless Shapeshifter that lets you choose a Creature type when it enters, and then makes all of your spells of that type cost WUBRG less to cast, this only reduces the colored mana you pay, and it even gives those Creatures a +1/+1 boost
With Miirym, generating Treasures allows you to cast expensive dragon creatures and copy them while keeping enough mana open for removal and counter spells
If you do, return up to two Rat creature cards from your graveyard to your hand
once a creature or planeswalker is in play it gets far harder for blue to deal with it, which is where the value of cards like Erode and Bitter Triumph comes from
Should we change the mechanic's name