Irish:
Gaelic High King's Blood: obtained for holding and completely controlling the de jure Kingdom of Ireland.
Liberator of the Welsh Celts: obtained by holding the Kingdom of Ireland and completely controlling the de jure Kingdom of Wales.

Scottish/Pictish:
King of the Scots and Picts: obtained for holding and completely controlling the de jure Kingdom of Scotland/ Pictland.
Scourge of the Saxons: obtained by completely controlling the de jure Kingdom of England.

Welsh:
Blood of Gruffydd ap Llywelyn: obtained for holding and completely controlling the de jure Kingdom of Wales.
Scourge of the Saxons: obtained by completely controlling the de jure Kingdom of England.

Breton:
Blood of Alan: obtained for holding and completely controlling the de jure Kingdom of Brittany.
The Liberator of Gaul: obtained by completely controlling the de jure Kingdom of France (West Francia).
Blood of the Old Celts: obtained by completely controlling the de jure Kingdom of Galicia in Iberia.

Available for all Celts:
Blood of the Celtic Conqueror: obtained for holding and completely controlling the de jure Empire of Brittania.
New Celtic Frontier Blood (not available for Bretons): obtained by completely controlling the de jure Kingdom of Brittany as a Scot, Pict, Irish, or Welsh character.
Blood of Vercingetorix: obtained for holding and completely controlling the de jure Empire of Brittania and Empire of Francia.

Russian, Volhynian, Ilmenian, Severian:
Blood of the Rus: obtained for holding and completely controlling the de jure Empire of Rus.
Proselytization of Rus: obtained by holding the a kingdom or empire title and converting to Catholic, Orthodox, or Iconoclast.
Conqueror of the Crimea: obtained for holding an empire title and completely controlling the de jure Kingdom of Crimea.
The Torment of the Tartars: obtained for holding an empire title and completely controlling the de jure Empires of Rus and Tartaria. Unavailable if you have taken decisions for the Slavic Union.
Blood of Velikiy Pyotr: obtained for holding an empire title and completely controlling the de jure Empires of Rus, Volga-Ural, and Pontic Steppe. Essentially taking the decision to recreate the Russian Empire. Unavailable if you have taken decisions for the Slavic Union.
The Blood of Slavic Reunification: obtained for completely controlling the de jure Slavic Union and the Kingdoms of Croatia, Serbia, Bulgaria, and Wallachia. Unavailable if you have taken decisions for the Empire of Russia.
Slavic Reformation Blood: obtained by being a Slavic Culture and reforming the pagan Slavic faith.
Bane of the Magyars: obtained for completely controlling the de jure Kingdom of Hungary. Unavailable if you have taken decisions for the Empire of Russia.