Tron's main deck has no blue cards, so Red Elemental Blast has nothing to hit and stays home. Standard Bearer is a cheap body that can soak up some of their targeted removal. While it is on the battlefield, Tron must target it if able with spells they cast and abilities they activate, such as Kaervek's Torch, Barrels of Blasting Jelly, and Giant's Boulder, which pulls that removal off our better creatures. It does not protect us from Pinnacle Kill-Ship, because that card's 10 damage comes from a triggered enters-the-battlefield ability, and Standard Bearer only affects targets chosen while casting a spell or activating an ability. It also works as an extra blocker while we race their slow ramp draws. Obsidian Acolyte adds another early body to pressure them before Tron assembles, which matters since this matchup is largely decided by whether we can close the game before they hit their colorless mana engine. Loran's Escape and Bitter Reunion are trimmed since protecting a single permanent matters less than applying steady pressure.