They use a spell or attack, and in that case you defend and draw more cards
If you care more about portfolio management than brewing, EchoMTG is excellent
But theres a few advantages here: You get to see all their hands and get the best card, but also, if they dont have good cards, all the better for you
That being said, if you don't fall into this category, Mega Evolution is a lot of fun to open
Cards like Terror, Fireball, and Mana Leak were offered in the first wave, and these were all classic cards with text that tournament players know by heart, with recognizable art, too
There are no brakes here like just once per turn or skipping the first card drawn in their draw step, just one card for them is one card for you as long as you have that mana