Hardest Boss Event

[weester9]

What is the hardest boss event you can remember, and how did you beat it (or how did you try to beat it)?

For me, it was that one week with Vortex on 190% speed on In the Loop.

[fractalgem]

Well, so far it was that vortex on a two lane track one a little while ago. Which i decided i wouldn't even bother trying to take on seeing as I both had a headache at a time and had either 0 or 1 paragons unlocked XD

[Shruburbs]

lych 10 farms
i died becayse i didnt make enough money for good defenses