Topsy Turvy — ruling 1

Steps within each phase play out as normal. For example, although the beginning phase happens last in a turn, the untap, upkeep, and draw steps happen in their traditional order. (If it were the other way, combat would require psychics to get through.)

Topsy Turvy — ruling 2

Any even number of Topsy Turvys (Turvies?) will essentially cancel each other out and return the order of phases to their normal order.

Topsy Turvy : règles, fonctionnement et interactions (MTG)

Topsy Turvy is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

The phases of each player's turn are reversed. (The phases are, in reverse order, ending, second main, combat, first main, and beginning.) As long as there are more than two players in the game, the turn order is reversed.

How it works : Topsy Turvy

Original English text — Wizards of the Coast / Scryfall

#1February 29, 2020· Wizards of the Coast
Steps within each phase play out as normal. For example, although the beginning phase happens last in a turn, the untap, upkeep, and draw steps happen in their traditional order. (If it were the other way, combat would require psychics to get through.)
No other card is named in this ruling.
#2February 29, 2020· Wizards of the Coast
Any even number of Topsy Turvys (Turvies?) will essentially cancel each other out and return the order of phases to their normal order.
No other card is named in this ruling.