Not sure about minimum stat requirement, those that are listed (Required Attributes) are just my stats on the heroes.

Very chill build with more DSTs. You want enough range on the gas (at hint 3 and 4) so that they even can stun mobs at hint 1 and 2 (you'll see it in the video below when I open the map).

I do also upgrade the gas traps once or twice to extend the duration. Since I have rather short duration on my gas they need to be upgraded for more safety, you can see goblins in the video are getting rather close during the first wave, reaching hint 1 and 2.

Make sure that your Ensnare can last the whole boss fight, that's why I upgrade mine (I tend to play safe).

Should be safe to play any character during the boss.

I am not a speed runner, but still managed to get a decent time. You can probably do it a lot quicker.

Fused Towers:
Ensnare.
Gas.
DST.

Build can completely be AFKd during waves (Not boss wave ofc) with high enough stats.

Video: https://drive.google.com/file/d/1qrn3XtobuxUhSS9OMDpHsTQj2D65cn3A/view?usp=sharing