Vlad is the final Boss hero and is recruitable in the Transylvania Campaign.
Unit Type - Cataphract: Reduces Damage Taken. Gambit - Blood Lust: Deal Gambit damage to a single target and heal up to the amount of damage dealt.
Vlad has a great gambit attack and unit type. He will prove very useful from the time you recruit him up through the Trojan Warriors campaign.
Unfortunately his Stats are low all around and his unit count/growth rate just don't allow him to be a lasting hero. Expect to be overpowered by mid-high ranking prestige heroes and enemies in the Hellenic Offensive Campaign and on.
He is recommended for his decent tank and damage mix up to about level 60. Find a better hero (Prestige) from there on.