To fight Krazzak or not, Magic Valley in Elf land

[Jamers]

So after I summon the turtle and he gives up all the crystals, there is an option to fight the orc shaman Krazzak or not to. If I don't fight him, I get the +3int, +10 mana Old Skull and a shop opens up, which is what I did on my first play through.

I'm just wondering: what happens if you do choose to fight him and win? Do you get a better item out of it? Does the shop have better troops / items available? Is the shop open at all?

Thanks in advance.