Hidden in Snow

[Zath]

How about this line of reasoning...

The mage is the only valuable unit produced by Hidden in Snow. This is evident when the Unfrozen are compared to other summons of the same level, such as trolls and ghosts.

Given the path requirements of this spell, the mage is only worthwhile if it gets picks in earth magic. Without picks in earth magic, you might as well just cast Streams from Hades for guaranteed water and death magic.

Disregarding pretender magic paths, the only nations with access to water and death magic to cast Hidden in Snow but lacking in earth are MA Caelum, EA/MA C'tis, EA Niefelheim, MA/LA Jotunheim, and EA Sauromatia.

Given the gem cost of this spell, the mage must get multiple earth picks to be worth the cost, otherwise you could just trade for some earth gems and use empowerment instead.

The expected number of mages per cast is 1 (random between 0 and 2), and the chance for each mage to get at least 2 picks in earth is 1/2 (from 3x 50% picks), so on average we can expect to spend 110 water gems for 2+ levels of earth magic.

Empowering two levels of earth from scratch costs only 80 earth gems, is guaranteed with no chance of failure, and can be used on any mage of your choice with the desired combination of magic paths.

Hidden in Snow is therefore a spell of very limited use, and still quite weak for its niche of providing earth magic to nations with water and death due to its unacceptable level of risk - just one or two failed castings will likely exhaust your gem supply and set you back many turns. This problem is further exacerbated in MP games where trading is allowed and one has the option to empower in earth without taking on such risks.

If the balance of this spell is supposed to be based on its performance in MP games, then it is certainly in need of improvement. One guaranteed mage with one guaranteed pick in earth magic would be a good way to start out, and you can reduce the chance of additional earth picks to keep its power level in check too.