A card might say, You may sacrifice a creature
If there's a cost associated with having that creature attack, you aren't forced to pay that cost, so it doesn't have to attack in that case either
Starlight Spectacular is one of the few eternal-legal pieces that initially stuck out to me as a possible all-star
On top of all that, Mangara, the Diplomat has lifelink, making it a great creature if you need to stabilize from a disadvantageous position
The cost to activate it may seem high at first, but when used at the right time, the card can almost guarantee victory
2024-06-07 Abilities that apply "when [this permanent] is turned face up" will trigger an additional time only if that permanent is colorless once it has been turned face up