Broken cards spoiling the game

Why are cards like Zephrys the great and Reno Jackson allowed?
I’m a new player and these just make a joke of the game and are just a crutch for people who can’t play fairly.
What’s the point in designing a deck to play to be undone by a joke of a card that can restore full life with no thought, or hardly any or a card that can totally ruin a game as you can just chuck it in?

I feel your pain blad…big up yourself for pointing these waste batty cards out.

All the cards in the late expansion are broken.
You can clear the board and fill the board at the same turn.
It was mostly impossible back then.

I would probably suggest playing standard as a new player, as you’ll be at less of a disadvantage in general. You have to remember that to play those cards, they have made their whole deck worse which is where the balance comes from. Once you notice there a highlander deck you can change you game plan up to play around it. Whether that be saving up surprise burst, so that you kill them when they have Reno in hand or kill them straight after they play Reno as the inconstancy of there deck means there follow-up to healing too full is weak, and you just kill them.

How do you consistently clear and fill the board on the same turn?