Ylthin in Heroes 5

All Unicorns, Silver Unicorns and Pristine Unicorn in hero's army gain +1 to their Attack and Defence for every two levels of the hero, starting on first level.

Hunted by a party of Dark Elf slavers at a tender age, Ylthin was saved from that gruesome fate by an avenging unicorn. Since that day she has worshipped those mysterious dwellers of the wood, and has dedicated her life to working with them. No one understands them better than Ylthin, and her knowledge enables her to use the unicorns’ swiftness and might in the most efficient way in battle.