Some arguments pro and contra go as follows:
- Auric' agenda is the restoration of Illians' power to assist him in his ascendancy to the position of the God of Winter. Almost a citation. Basically it is a step to restore the divine power balance shattered by multiple godslayings, analogical for Cernunnos stepping in to replace slain Sucellus (yet another question - who of them is also known as Cenarius?

) I am unsure whether he intends to again bring the world into the total and disbalancing winter - if he does not, his goal imo (which is based on D&D definition of 'true neutral' alignment) qualifies as neutral with leaning towards the good.
- Atrocities committed by Auric himself and Illians altogether that i had found in presented texts do include: leaving heavily wounded men in snow - lack of compassion but also lack of malevolence (such as torturing them before leaving or eating them alive) - act once again qualifies as neutral; training frost giant upon the captured prisoners - act of evil as necessary as any living weapon production, war horses, mammoths, other beasts of war. Btw, war itself in D&D is nominated as a neutral act.
- Ascendancy to power is generally regarded as evil (by everyone who already have it - the classical example may be Spell of Mastery from MoM).
- Ice as elemental power lies on the planes of neutrality.
- Auril, the Forgotten Realms goddesss of frost and cold and such, is labeled as evil - but once again, she desires to spread her icy dominion all over the world(s).
- Ayrin, the Frostweaver dragon, elven worshippers from first and true Spellforce are said to 'possibly no longer be the followers of Light' - so wielding ice power alone is but a reason for doubt about categorizing them as good or neutral.
- I haven't found any evidence of Auric' and Illians' allegiance towards Agares and demonic forces (even Mulcarn himself, as i perceive it, was hoodwinked but not corrupted) which apparently serves as the primary characteristic in FfH to qualify for 'EVIL'.
- Gameplay reason: when i played Illians in all-civs-present mode on huge map, my best relations were with goods and neutrals, even despite my "evil" mark, simply because they were not interfering with my slow amassing of power in form of expansionist/perfectionist global strategy (how else is it expedient to research and build that Ascension project?) and often even helpful by providing trade, recon and resources while evils were quite detrimental to my cause by casting their global spells and attempting conquests upon my territory.
http://forums.civfanatics.com/showthread.php?t=264496&page=152