Leyline of the Guildpact has some utility in Commander too, where cards like The Mana Rig, Fallaji Wayfarer, Hero of Precinct One, and Rienne, Angel of Rebirth might fit together with the Leyline in a Jenson Carthalion, Druid Exile deck
Murmuring Bosk
If that spirit then leaves the battlefield, the original card goes to your graveyard
The cost is a bit steep as youll need to keep your Harmonized Trio around and tap two untapped creatures, but I can see it being particularly useful in Izzet spellslinger decks where you need regular small spells
Clouds Limit Break Im loving the new direction were seeing for white sweepers
Finally, Deathmark will help Black decks stave off any Green stompy or White aggressive decks, but for now it'll stay on the sidelines