Sivitri, Dragon Master — ruling 1

A player who controls a creature that “attacks if able” can decline to pay additional costs to have that creature attack. If they do and there’s no other player or planeswalker to attack, that creature simply doesn’t attack.

Sivitri, Dragon Master — ruling 2

In a Two-Headed Giant game, creatures can attack your teammate and planeswalkers your teammate controls without requiring a life payment.

Sivitri, Dragon Master : règles, fonctionnement et interactions (MTG)

Sivitri, Dragon Master 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

+1: Until your next turn, creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures. −3: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle. −7: Destroy all non-Dragon creatures. Sivitri, Dragon Master can be your commander.

How it works : Sivitri, Dragon Master

Original English text — Wizards of the Coast / Scryfall

#1September 9, 2022· Wizards of the Coast
A player who controls a creature that “attacks if able” can decline to pay additional costs to have that creature attack. If they do and there’s no other player or planeswalker to attack, that creature simply doesn’t attack.
No other card is named in this ruling.
#2September 9, 2022· Wizards of the Coast
In a Two-Headed Giant game, creatures can attack your teammate and planeswalkers your teammate controls without requiring a life payment.
No other card is named in this ruling.