Cant kill the bloody spider

[Hearts]

Go park your main fighting team somewhere (maybe put three in a castle and keep your other two in reserve). You are probably going to take some losses in this fight so it's a good idea to do this with "throwaway" troops.

Get the Might skill called "Frenzy" so that you get bonus attack power for killing troops. This will add up like crazy.

If you're a magician, Magic Axe can deal some great boss damage. He also doesn't retaliate against your magic spells, which is nice. Also if you're lucky enough to have Calm Rage I'm sure that is a huge plus (I didn't have it).

My party was:

Jarls
One stack of every kind of snake
Trolls

The trolls get a bonus for fighting in a cave, and their attack buffs every time you kill something. They also regenerate all their health every turn. For that reason they are really good in this fight. You might not even lose one.

Strategy: Just focus on killing the baby spiders. Frenzy will build up and make you just strong enough to consistently kill all the enemy stacks while taking hardly any losses. After doing this for a while your snakes will have ridiculously high attack power and you can just sic them on the boss. Or, you can just pick the boss off with magic spells if you have good magic damage, and let the snakes take care of the baby spiders (that's how I did it).

Don't worry, it's one of the hardest fights in the game and it's supposed to be. It's okay to find it particularly challenging.