Endless mode 2+ achievement

I’ve been trying this for a few days now and I can’t get past wave 90. I’d rather not try again until I can think of something different. Are there any last suggestions out there?
I’ve respecced my party to take out as many of their defensive skills as I can and I’m trying the all-dragon backstop approach, but I feel like I’m missing something. I’m using the slow start and chain lightning books (wouldn’t it be cool if lightning stun worked with chain lightning).

Got it. Shock lightning instead of chain lightning.

I’m bumping this thread because now this is where I’m stuck, I can get to around wave 85~ but after that I soon get overwhelmed, I’m at a loss now so I need some advise or tips on breaking the 100 wave mark, I figure its all about unit spec’s and unit behavior settings at this point. What spells for Azra did you guys use, and did you just spec every unit for maximum AoE?

Well, you might start by telling us how are your characters built. Or zip up and attach your savegame, so that we can have a look and tell you what we’d do differently…

I actually got it now, to wave 115 no less. Using Lightning Shock made a huge difference by it self adding maybe 15 waves, additionally I moved some Dragons around for better coverage for a nice Stun wall effect which really helped.