For insomnia, take advantage of pikemen surrounded swampland to protect yourself on one side - the enemy needs a hero to take swampland protected by a pikeman, which they're not going to bother with while fighting someone else. This lets you focus your forces on one enemy, and once you can get their mines, you've pretty much got the map won.
Dug through the script for the artifact descriptions. In order, they're: +200% to demons (multiplied), +200% to undead (multiplied), +200% to drowners (multiplied), +200% to warlocks (still multiplied), shift + click to press a button 25 times per second, +100% resources while collecting mushrooms, +5 hell ashes now and after restart, +5 bone flour now and after restart, and +5 magic powder now and after restart. The hidden ones are +25% hero experience, +100% gold gain, and +1 starting SP.
The tier 3 nidhoggs (bulky armored and firey tail) appear to have their abilities switched; the type A evolution has the all+heal while the type B has the single target ability.
Encountered a bug: Invasion countdown is stuck, simultaneously showing 900s and the standard idle text. Dragons Den displays a dragons that doesn't belong there and won't allow me to access it. The dungeon level is stuck at 10. Despite having 999,999 food, I can't enter the dungeons. After waiting, the invasion triggered as normal, and each of my dragons were present. The invasion text appears to be normal, but now the dragon den only shows one dragon and I still can't get in.
 "Konkr.io"){kind=icon}
 "Random Number GOD Idle"){kind=icon}
 "Underworld Idle"){kind=icon}
 "Your Chronicle"){kind=icon}
 "Dragon Fortress"){kind=icon}
 "Pingy the Ping Idle RPG"){kind=icon}
 "You are a... The Sequel"){kind=icon}