The high-pitched whirl of a hook is the only battle cry she needs.

Kor Bladewhirl

Rally — Whenever this creature or another Ally you control enters, creatures you control gain first strike until end of turn.

The List

Battle for Zendikar

Rally — Whenever Kor Bladewhirl or another Ally enters the battlefield under your control, creatures you control gain first strike until end of turn.

If a creature with a rally ability enters the battlefield under your control at the same time as other Allies, that ability will trigger once for each of those creatures and once for the creature with the ability itself.

When an Ally enters the battlefield under your control, each rally ability of the permanents you control will trigger. You can put them on the stack in any order. The last ability you put on the stack will be the first one to resolve.