Defeating the spider on impossible

[Metathron]

Guess what, there aren't any royal thorns in my game, so that strategy's out the window.

I could leave the spider for later, when my hero is stronger...and has elves.

I could split the shaman into two groups...

I could hire thorn hunters to raise new plants from dead spiders...

Not sure which of these I'll do, probably the first one.

EDIT: I defeated the spider by going the double shaman route, closing up those empty spaces. Took 45 rounds and lost 15 royal snakes, but that's a small price to pay for my sanity, I'd say.