Players usually can only play one land card per turn, with most land providing a specific color of mana when they are "tapped", usually by rotating the card 90 degrees to show it has been used that turn
Cards can be changed if theyre too powerful (either by having a higher mana cost or by having abilities removed) or if theyre not powerful enough (either by having a lower mana cost or by having abilities added)
The first one is well addressed by bracketed play through the restrictions on combos and a lower overall density of extra-turn effects
Without Standard to worry about, the designers went wild with the power level
Who are the characters who would be most appropriate to fight in a second Phyrexian Invasion
Killer's Mask - Friday the 13th Let's Play a Game, Grab the Prize, Trial of Agony - SAW Osseous Stickwalker - a living Wickerman Unstoppable Slasher - Halloween's Michael Myers Clockwork Percussionist - Stephen King's The Monkey Haunted Screen and Cursed Recording - The Ring Ragged Plaything and Arabella, Abandoned Doll - Anabelle Vicious Clown - Child's Play Anthropede - A literal Human Centipede Altanak, the Thrice-Called and Say Its Name - Beetlejuice, Bloody Mary, or Candyman Break Down the Door - The Shining Omnivorous Flytrap - Little Shop of Horrors Disturbing Mirth - All the Razorkin are part SAW, part Hellraiser, but this one gives off particularly Cenobitey vibes