Actually, the Invincibility serves a purpose. It makes it to where there is absolutely no way to remove it by normal means (if at all if you can't attack it). That and there are far better places to grind.
Also...these Dark World maps are absolutely insidious. I've got 11 of 16 I've opened (of 43) cleared and the five I can't are either because I absolutely hate the gimmicks involved or (in one case) I don't have the levels (at 1500+) to beat it.
The shot I showed is one of the far easier Dark World maps.
In order to get Land of Carnage open, I need 25 of these maps beaten of 43.
Not fun. These maps are absolute pain with the geo panel crap.
EDIT: Boosting the )(@# out of Marjoly and I'll tell you why: First off, her INT is phenomenal from the get-go, second she has a nice little Evility which boosts her INT 100% upon Attack Magic use and finally I now have another Evility on her that causes her to gain 10% INT every time she takes something out on the map. 30 kills? +300% INT.
I have Fire +9, I'm having Adell use his Evility Mercy (always leaves one 1HP when enemy is lower level), Big Bang +4ing HoO4 to leave 1 HP on some Lv. 1384 Genociders in a 3x3 and then having Marjoly cast Fire+9 3x3 on them.
To say the least, as long as Marjoly has the SP she will ALWAYS HIT...I'm fairly surprised that she could hit Lv. 1834 Genociders with her HIT stat at level 1, but she can. That was 200 levels right there.
Hopefully, I'll get to a point where I can do Omega Fire+9 on these guys but dang...it was hard enough getting Fire+9 and I'm at Mega Fire+7 and +8 requires 81920 mana...
____________________
|  |
| |
|