Death worship and huge maps
From what I have observed so far, death mages with the aforementioned perk lategame are pretty much walking gods. Once you have 6+ death nodes and a decent level mage character your dirge and howl (if you took water) can level armies with 1 or 2 spells quite readily, this is not difficult to accomplish at all with the ability to convert any node to a death node.
Not to say that a faction that focuses on having a powerful mage for their leader shouldn't be a force to be feared, my concern is two fold. Firstly the larger map size will elevate their power to absurd amounts currently I have seen mid 30 ticks on dirge quite readily and that is over 300 dmg to an entire army with a spell that has no cast time. Granted most fights don't last 10 rounds, but then again most units don't have over 60 hp. Secondly if this is intended, then why is it restricted to empire mages with a specific faction perk? I honestly don't mind having powerful lategame mages, however I don't think limiting it to such a specific set of conditions is good for gameplay.
Any thoughts on this would be appreciated.