"Necropolis" - changes to creatures of levels 6-7.

Resistance to Earth is used twice. What about Crystal Scale?

Yes, Scale too (immunity to death effects).

Could you describe the main concepts of the WGE mod? It's hard to find everything on the website in the discussions, or is there a lot of content there?

There is a lot of content. The main concepts are in the very first posts of the topic; the rest is discussion. In short, what is currently implemented is dedicated exclusively to tactics and, in particular, to the duel mode. All units were created from scratch (although for many, a similarity to the original can be traced), abilities were enhanced, there is a characteristic decrease in speeds (more maneuvers), the introduction of a heavy class, a significant enhancement of abilities, diversity of units (no similar ones), 3 alternatives for creatures (instead of 1 + 2 upgrades), and an increased role of stats. Of the new models, Ifrits, Golden and Azure Dragons, Emerald Dragons (modified), Dark Devastators (replacing Dark Riders), and Ice Dragons are used. It is better to leave comments about this mod in the corresponding topic.