How does the elf level 2 magic ability work in Ultra Tiny Epic Kingdoms?
A similar post for the 1st edition rules is on boardgamegeek. The designer says:


  Actually, it's not ... The "+1 War Power" is a resource discount (you can bid 7 but only pay 6). This is much clearer in 2nd edition.


This implies that you can dial an odd number and pay the even number cost.

For the solo play, this only useful if the war cost is odd.