Strionic Resonator

Triggered abilities use the word "when," "whenever," or "at." They're often written as "[Trigger condition], [effect]."

If a triggered ability is linked to a second ability, copies of that triggered ability are also linked to that second ability. If the second ability refers to "the exiled card," it refers to all cards exiled by the triggered ability and the copy. For example, if Fiend Hunter's enters-the-battlefield ability is copied and two creatures are exiled, they both return when Fiend Hunter leaves the battlefield.

The source of the copy is the same as the source of the original ability.

Any choices made when the triggered ability resolves won't have been made yet when it's copied. Any such choices will be made separately when the copy resolves. If the triggered ability asks you to pay a cost (such as that of Frenzied Goblin), you pay that cost for the copy.

Strionic Resonator targets a triggered ability that has triggered and is on the stack and creates another instance of that ability on the stack. It doesn't cause any object to gain an ability.

If the triggered ability divides damage or distributes counters among a number of targets (for example, the ability of Bogardan Hellkite), the division and number of targets can't be changed. If you choose new targets, you must choose the same number of targets.