Thistle and Whistle

Alliance (Choose a player. If that player agrees to an Alliance, creatures they control get +1+1 and cannot attack you or a planeswalker you control. The Alliance ends when you attack the allied player.)
When Thistle and Whistle enters the battlefield, create Thistle, a legendary 2/1 blue faerie creature token with flying and "Whenever this card deals combat damage to a player, that player can't cast creature spells during their next turn."