We dont need all Merfolk, but we do need some
Players focus on generating energy quickly and spending it to fuel creature buffs, card draw, and damage output
Then again, you might be running a spell slinger deck, with lots of cantrips like Stella Lee, Wild Card, where you want to filter through your deck, draw cards, and stop people from getting there before you combo off
At this turn's next end of combat, destroy all creatures that were blocked by that creature this turn
Other Maze's End decks could use 5-color commanders like Child of Alara to control the board with wraths until you can assemble your gates, or Garth One-Eye to consistently cast Black Lotus into a pile of ramp to get all your gates out at once
You can also keep casting Sculpting Steel as a copy of The One Ring that dies to the legend rule to get its ETB again and again