It seems impossible to achieve "brilliant" in level 12. The final wave contains this "Fast smoke bomb champion". I've put both a fast hitting sniper Den on the first tile next to the entrance (to ensure max damage and instant cloaking of the rogue when he enters), and the maximum amount of (well upgraded) towers around the first diamond.
However, although the rogue cloaked instantly on entering, he only uncloaks after he took the first diamond. Even hitting him with upgraded meteors wont kill him before he touches the diamond.
Any advice anyone, or is this something that has to be tweaked in a next version of the expansion?
 "Enigmata 2: Genu's Revenge"){kind=icon}
 "Cursed Treasure: Level Pack!"){kind=icon}