Surge of Salvation doesn't prevent damage from transformed U/R creatures.
Opponent's first main. They cast a removal spell on one of my creatures. I cast Surge of Salvation in response. It counters it. Then my opponent goes to combat later in that turn. They attack with 3 U/R creatures. They deal damage when surge prevents damage from red sources. It didn't prevent damage.
The creatures in question were U/R elemental tokens and a flipped Khenra Spellspear/Gitaxian Spellstalker.
Surge of Salvation doesn't prevent damage from transformed U/R creatures.
Opponent's first main. They cast a removal spell on one of my creatures. I cast Surge of Salvation in response. It counters it. Then my opponent goes to combat later in that turn. They attack with 3 U/R creatures. They deal damage when surge prevents damage from red sources. It didn't prevent damage.
The creatures in question were U/R elemental tokens and a flipped Khenra Spellspear/Gitaxian Spellstalker.