So I just made it to the second island after just a few dead units (slingers, berserkers) on the first island. I finally find a hut selling those mounted valkyries (or whatever they are from the training mission), but there are only 3... and I can field 7. I hate the limited supply... just like only being able to get 3 soothsayers on the first island (well, that's all you really need, but still).
So, since they are in supply, now I'm trying the lvl 4 viking guys with 240 hp - tough guys tend to be the easiest for me to manage. I'm debating using the alchemists (high lvl dwarfs) just because they are higher level, but want to scout the rest of this island and the next first.
So I found the first valkyrie and she's in my hero screen now. How do I use her ability, and do I want to? I spoke to her about it and I guess it only triggers if I lose troops. Do I need to speak with her before battles to have it "readied?"