RELIGION:

INSULAR CELTIC RELIGION
Magic: Warmagic: The Druids of the British Isles use powerful war magic to spur their allies on to perform great and legendary feats in battle.
Rituals: Mild to severe human sacrifice (rare), bone reading, chanting, body paint for picts

Northern Spanish Celtic Religion
Magic: Enchantment and illusion
Rituals: Altar magic, sacrifices, chanting, entrail-reading, horse blood drinking

Brittany Celtic Religion
Magic: Warmagic
Rituals: Same as Insular celts with more sacrifice, more bone reading, and a focus on megalith creation and use

Scandinavian Paganism
Magic: Weather magic and divination, for far-seeing, rain and wind.
Rituals: Rune reading, dancing, sacrifice
SPECIAL: Berserkr are people born with the instinctual ability to cast war magic on themselves. They must meditate on their rage before battle to embrace their berserkr rage. Their magic is fueled by combat and bloodshed

Germanic Paganism
Same as Scandinavian Paganism, but the Gods have slightly different names.

Catholicism
Magic: Arcane, light
Rituals: Conversion, mass, prayer, mortification of the flesh

Orthodoxy
Magic: Arcane, Defensive magic
Rituals: Vigils, fasting, prayer, the Divine Liturgy

The Cult of the Dark Lord
Magic: Blood magic, fire magic
Rituals: Regular, brutal sacrifice, suicide, torture, blood-drinking and bloodletting, regular worship of the Kabbah and the Dark Lord, severe mortification of the flesh, cannibalism
Special: Priests of the Cult are exceedingly rare, even more so than the priests, patriarchs, druids, gothi, etc. of the European religions. To compensate for this, their mages are extremely powerful.