To see all Life ended
UG is usually the basis for all landfall decks in Commander (unless youre in Jund colors, which well get to in a moment)

Ajani, Nacatl Pariah Arahbo, Roar of the World Arahbo, the First Fang Balan, Wandering Knight Bast, Panther Goddess Brimaz, Blight of Oreskos Brimaz, King of Oreskos Cait Sith, Fortune Teller Denry Klin, Editor in Chief Falthis, Shadowcat Familiar G'raha Tia G'raha Tia, Scion Reborn Jareth, Leonine Titan Jazal Goldmane Jedit Ojanen Jedit Ojanen of Efrava Jedit Ojanen, Mercenary Jetmir, Nexus of Revels Kaheera, the Orphanguard Kemba, Kha Enduring Kemba, Kha Regent Kimahri, Valiant Guardian Kitt Kanto, Mayhem Diva Kros, Defense Contractor Kutzil, Malamet Exemplar Leori, Sparktouched Hunter Lurrus of the Dream-Den Marisi, Breaker of the Coil Mirri the Cursed Mirri, Cat Warrior Mirri, Weatherlight Duelist Nazahn, Revered Bladesmith Nethroi, Apex of Death Nethroi, Apex of Death Old Hob, Alleycat Blues Phabine, Boss's Confidant Prava of the Steel Legion Purraj of Urborg Qala, Ajani's Pridemate Raksha Golden Cub Rigo, Streetwise Mentor Rin and Seri, Inseparable Roxanne, Starfall Savant Runadi, Behemoth Caller Sally Pride, Lioness Leader Silvar, Devourer of the Free Snapdax, Apex of the Hunt Snapdax, Apex of the Hunt Soul of Windgrace Sovereign Okinec Ahau The Lion-Turtle Tigra, Feline Fury Vadrok, Apex of Thunder Vadrok, Apex of Thunder Wasitora, Nekoru Queen Y'shtola Rhul Y'shtola, Night's Blessed Ygra, Eater of All Zahur, Glory's Past Zar Ojanen, Scion of Efrava

Let's take a look at some of this data applied to current Standard staples and other cards of interest
Its totally possible to have just one daybound/nightbound creature in your Modern or Legacy deck, where the time of day may feel like a bit of extra text on that one card
In looking over the deck lists, one of the decks in particular jumped out at me as being particularly synergistic and primed for easy upgrades