Nimbus, Arcane Companion

Walker of Realms - {w}{t} Commander creatures you control phase out.
Master Transmuter - {u/r} Exile an instant or sorcery card from your graveyard, draft a card from Nimbbus, Arcane Companion's spellbook.
Familiar's Bond - When you cast a spell that targets only Nimby, Arcane Companion, copy that spell, the copy targets Arno, Arcane Inventor. And vice versa.
Partner with Arno, Arcane Inventor