silver border mtg cards Black Border, White Border, - What Do They… A collection of Silver-Bordered Commanders.

If this creature's emerge cost was paid, instead create X of those tokens, where X is the sacrificed creature's toughness

Almost all of them have their niche in Standard

Reforge the Soul Time Ebb Write into Being Land: 14 Island 7 Mountain Bonders Enclave Desolate Lighthouse Forge of Heroes Forgotten Cave Hall of Oracles Lonely Sandbar Reliquary Tower Remote Isle Rivendell Rogues Passage Shivan Reef Smoldering Crater Steam Vents Sulfur Falls Temple of Epiphany Tyrite Sanctum Life, Backwards Without some form of deck manipulation, Rivers first ability isnt much different from normal card draw through a randomized deck, except your top deck is physically safe from mill

You were probably subconsciously influenced by Cosmic Encounter

4 Winterspell Give It Time

Since there's no sideboard, you may want to consider maindecking some artifact or enchantment hate, especially if those are themes of the format