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Honestly, I don’t quite understand the fundamental difference between Galthran and Necro specialists. The hero class itself gets free troops, while other ways of recruiting troops (external dwellings, Griffin Conservatories, Dragon Fly Hives) are also present. So there is a certain bonus, which in itself can be seen as unfair, but that’s not what I’m talking about. This bonus is enhanced by heroes like Isra and Vidomina due to their specialty, but a rule regarding Expert Necromancy was introduced for them. And this bonus is also enhanced by Galthran, and his impact on the enhancement might be even stronger than that of Isra/Vidomina — it seems more than logical to nerf this hero. Actually, why go far — why not introduce an Expert Necromancy restriction for Galthran as well? This would increase the chance of ruining his skill tree, which is a decent fix in my humble opinion. This would also help in a situation where someone just buys him out of the tavern.
Regarding the Grail — I think that if it didn’t exist, it would be necessary to invent it (c). But seriously, either ban it in Conflux and Tower due to the imbalanced bonus, or rework its bonuses for these two towns in Heroes, if that’s possible.