Tron's clock comes from Bramble Wurm, Nyxborn Hydra, and Writhing Chrysalis tokens, and Breath Weapon deals 2 damage to each non-Dragon creature, sweeping their Eldrazi Spawn tokens and smaller creatures while chipping Nyxborn Hydra. Pulse of Murasa gains 6 life to offset their big creature damage and can recur a key threat or land you lost to their own Thermokarst-style effects. Your land destruction suite (Thermokarst, Mwonvuli Acid-Moss) is excellent here already and should stay in at full count to deny their Urza land trio. Annoyed Altisaur and some copies of Malevolent Rumble are the easiest cuts since they're slower value pieces you don't need against a deck that's also trying to ramp.