Haven vs. Chaos

I think Life is actually the most useless magic for Chaos (for my playstyle). It's designed for army building, and I mostly have only Dark creatures, except for the final battle. It's better to choose Order (even though it's not great for me either; I choose it if I need to steal something from Life or Order).

Yes, Life is only useful to Chaos because of Exorcism. ZYbr is right. Otherwise, it will be really difficult, especially if Order is well-developed.
But it's interesting what can be stolen from Order. Accuracy and Mirage? I don't think that would be a tactically sound move for a Chaos player. And from Order's side too (you can cast better spells on the opponent).