Ideally, you would play a Bodyguard like Nani, Protective Sister or Pluto, Determined Defender the turn you quest with Lucky to keep him safe from challenges
While other cards over the years have featured effects similar to this (mythic rare Zur, Eternal Schemer from Dominaria United comes to mind), Opalescence was the first to do it en masse for enchantments, and, due to its novelty and being first on the scene, it clocks in with a price point approaching $30
Its raw damage output isnt huge, so it wont score KOs quickly, but Raikou ex's utility makes it stand out
Several options exist depending on whether you prefer hunting through sealed packs or buying singles directly
Armed Dragon Thunder LV3 X WIND Level 3 [ DragonEffect ] ATK 1200 DEF 900 This card's name becomes "Armed Dragon LV3" while on the field or in the GY