NHF – new heroes for Heroes V 3.1.

Here's what I think: the "Devil's Chain of Biara" would suit Solmyr better because this chain deals air damage (it doesn't affect units with air immunity) and is enhanced by the "Trident of the Titans," and so on. In other words, this cast is related not to fire and demons, but to air, and Solmyr's spells are precisely related to the "Chain Lightning."