Speed running final boss? (*Spoilers*)

[khamiel]

Because I'm a masochist, I've been playing around with speed killing the final boss. Nothing particularly interesting to report, but I've had some (slightly unpredictable) luck killing his first form in about 5 seconds. Turns out that a well placed nature form thorn spike will rip his face up but good. Because the spikes basically ignore wraparound armour, I've also been looking at using them to deal with his shellfish form as well, but I can't find an effective way to do it.
Don't get me started on the second form experiment - that boy just won't sit still, although with a bit of luck I have tagged him with a ceiling mounted spike.
Anyway, has anyone come up with good ways to bring him down fast?

[Xiagan]

Abut the third form: You can lure him back in the tunnel until he gets stuck (that will happen). Then he'll hold still for your plant. Only problem may be that it needs too much time to bring him to that place...

[khamiel]

Yeah, it's a little too time consuming. Once you get him to the point you can lure him he's basically just fodder for Energy form - unless I'm missing something, and he can be lured earlier. Annoyingly, he seems to be completely invulnerable while he's retreating through the windy tunnel.