Apex Packmaster

Beasts, companions, and willing allies of your choice in the emanation become a perfect hunting pack. They gain +15 ft. speed, advantage on melee attack rolls while another affected creature is within 5 ft. of the target, and advantage on STR, DEX, and WIS saving throws. Once per round, when one affected creature hits a hostile creature, another affected creature may use its reaction to move up to its speed and make one attack against the same target.

This power has its own stable page so it can be linked from any character, item, location, story post, bargain, curse, or future reward.