I tried Fire Apocalypse: difficult a few times this week. To my surprise, it wasn't difficult at all. With some 4* and 5* cards and a 6* healer, I can pretty much auto-spin my way through. The thing is, I haven't gotten any rare chest drops yet in about 8 tries and I really don't have much use for another dozen zombie warriors.
Is the drop rate really that low or am I doing something wrong?
Are the rare drops themselves worth anything, or is it just the stage bonus card?
What kind of HP/skills does Insane require?