mtg cards that double triggered abilities Trigger duplication question : r/mtg The 36 Best Ability Copying

Once a creature has attacked, this can be any time the turn it declared an attack, they can pay the Boast cost once to activate its effect

Here's my Commander: She costs five, has flash and convoke, double strike, and gives your tapped stuff hexproof to protect them from removal or interaction

After the first time you foretell this, I promise you that your opponent will be panicking that every single foretold card is a copy of Starnheim Unleashed

In the rare case where enough -1/-1 counters are put on Aerith Gainsborough at the same time to make its toughness 0 or less, the number of +1/+1 counters on it before it got those -1/-1 counters will be used to determine the value of X in Aerith Gainsborough's third ability