Spider no loss without Magic Spring ?

[Xev]

Victory!
after many hours where i tried this spider boss with no-loss/no mana spring i had the luck to succeed in 58 rounds

Trolls were 4/1/1 (only 4 stack attacks, other only defend).
All other tries with 1 of 2 units get perma-web when boss is below 8k.
Winning key were the correct positions and using only stoneskin 1.
Have a look at this picture to get all informations.

Best wishes to Youpiya to get another winning solution!