Abenteurer (Civ4 FFH)
This is the primary Great Person obtainable by the Grigori. In essence, it is a hero unit that can be upgraded to almost any human unit, including Melee, Recon, and Arcane units. Since Adventurers retain promotions as they upgrade, it pays to use adventurers throughout the game, upgrading whenever you get the chance.
Ein Abenteurer ist ein Held, der zu jeder Nahkampf-, Bogenschützen-, Berittenen-, Erkundungs- oder Zaubereinheit aufgewertet werden kann, die die eigenene Zivilisation bauen kann.
One of the best things about the Cassiel of the Grigori is his Adaptive trait. The same applies to the Adventurer Unit. It is very adaptive to any playstyle and can be made all the more powerful through the adaptive trait. For example, if you follow the magic route then simply adopt the Arcane trait and make your Adventurer's into Adepts and you'll have summoners and archmages very fast. If you follow the non-magical route, then adopt the aggressive or raider trait. In any case, an Adventurer levels fast and is the Grigori proof that any person has the capability to become a hero.