They get better in multiples, too
If a card is too powerful, then it likely will change how future cards are printed to avoid repeating the disastrous monster that somehow got released
In clear succession to my article about Batteryman 9V, heres a deck profile of how Ive been using the card
Take 1 Level 4 or lower "Evil HERO" monster from your Deck, and either add it to your hand or Special Summon it, also you cannot Special Summon monsters from the Extra Deck for the rest of the turn, except "HERO" monsters
I already mentioned a sizeable amount of the Spell cards, like "Iron Core of Koa'ki Meiru" (as cost for some card effects and to keep your monsters alive), "Diamond Core of Koa'ki Meiru" (searcher and destruction protection), "Fire Formation - Tenki" (another searcher) and "Core Overclock" (ATK steroid), but there are some more
And the good news is that our AI for card recognition is so powerful that we can extend it to other games