Even though it isn't strictly a Landfall ability, a card like Gigantoad that cares about the number of lands that you control is also a good option for this type of deck
Planeswalker Nissas +1 offers a steady stream of card advantage/ramp and a somewhat menacing -7 ultimate
Angel's Grace is a key card in the Modern Ad Nauseam deck which MTG Goldfish values at just under $11
Hardened Academic Heroic Reinforcements Hofri Ghostforge Invasion of Kylem Judoon Enforcers Kassandra, Eagle Bearer Kolodin, Triumph Caster Legion's Initiative Lorehold Command Lorehold, the Historian Mabel, Heir to Cragflame Markov Waltzer Meddling Youths Merry, Esquire of Rohan Midnight Mayhem Mothers Yamazaki (playtest) Munda, Ambush Leader Nahiri's Resolve Nahiri, the Harbinger Nahiri, the Unforgiving Oath of Eorl Odric, Blood-Cursed Otharri, Suns' Glory Outlaws' Merriment Path of Mettle Phyrexian Skyflayer Pia Nalaar, Consul of Revival Razia, Boros Archangel Rem Karolus, Stalwart Slayer Riders of Rohan Risona, Asari Commander Scurry of Gremlins Seedglaive Mentor Sentinel Sarah Lyons Shadowfax, Lord of Horses Skyknight Legionnaire Spark Trooper Sunhome Guildmage Sunrise Cavalier Swooping Pteranodon Tajic, Legion's Edge Tenth District Legionnaire
