Killing a scary creature is great and all, but handing your opponent a very relevant body to do it doesnt seem like a great plan
In Onslaught , for instance, has cycling cards that interact with morph
They'll cast powerful spells, call upon classic summons, and even visit their favorite locations on the back of a Chocobo
And here's what happens, once you start drawing from this, your foe's will be like, "Well, they're already drawing from others, so I shouldn't worry about it and pay the tax." And then you draw more
Proliferate effects and counter doublers like Hardened Scales allow you to pump this up
It's all well going card-for-card with your opponent if all you're looking to do is keep them from doing anything, but to win the game, you have to get ahead