Steel of the Godhead is a common Enchantment — Aura card from The List (PLST), collector number SHM-150. Current market price: $1.90, TCGplayer market prices via Scryfall.
Enchant creature As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.) As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.