Surfing through forums I have made the conclusion, that quite a few are considering the Samhain ritual quite useless. Sure, if the AI uses it, it is a big nuisance, but for a human player it's impractical, because you're damaging yourself potentially a lot of more than your opponents, because the AI starts with many soldiers and gets a lot of free xp. For Elohim which caught an Ilian city it's probably better because of their worldspell, but it's never worth this investement. In a pure MP it would be quite good in combination with Stasis, but in a SP or a mixed MP it will mostly harm yourself.
So I came up with an idea: Couldn't Samhain summon an extra civilization into play similar to Infernals and Mercurians (only that it comes much earlier)? This civilization starts in war with every civilization except civilizations with Ice mana (or just the Builder of Samhain) and can't negotiate with civilizations without Ice mana (or just the Builder of Samhain). You're NOT allied with that civilization like Mercurians, but you have someone who attacks everyone else and therefor is kinda your ally. If you want a big challenge you could even consider making the Frostlings playable with Mokka as their leader. The special ability of the Frostling civilization could be that they all have affinity +1 for each Ice-mana (instead their +1 cold as it is now), you are the only one being able to build ice mana nodes and you can work ice tile even better than Ilian (+3 food on ice), but on other tiles you get less (-1 food on grasland and plains) and you don't have the terraforming abilities of the Ilians, instead ice slowly spreads through your territory (1% chance for each tile to be converted to ice)
So I came up with an idea: Couldn't Samhain summon an extra civilization into play similar to Infernals and Mercurians (only that it comes much earlier)? This civilization starts in war with every civilization except civilizations with Ice mana (or just the Builder of Samhain) and can't negotiate with civilizations without Ice mana (or just the Builder of Samhain). You're NOT allied with that civilization like Mercurians, but you have someone who attacks everyone else and therefor is kinda your ally. If you want a big challenge you could even consider making the Frostlings playable with Mokka as their leader. The special ability of the Frostling civilization could be that they all have affinity +1 for each Ice-mana (instead their +1 cold as it is now), you are the only one being able to build ice mana nodes and you can work ice tile even better than Ilian (+3 food on ice), but on other tiles you get less (-1 food on grasland and plains) and you don't have the terraforming abilities of the Ilians, instead ice slowly spreads through your territory (1% chance for each tile to be converted to ice)