Thats because Rainbow Rares are also in the vast majority of cases Secret Rares
equip this card to that target, OR: Unequip this card and Special Summon it in Attack Position
Tutors themselves break a fundamental rule of most card games , which is that you're at the mercy of the cards you draw
In the end, the Metalfoes are specifically good at serving as a Pendulum Engine for archetypes with monsters between 2 and 7 that specifically activate when destroyed
Again a mixed bag here, but we've got some absolute banger reprints like Reanimate and Ruinous Ultimatum, plus for new cards the commanders are great (as always) and we've got some crazy good new cards like Kefka, Dancing Mad which is one of the best reanimate targets
Or stadiums, or equippable tools, and so forth