Is it just me, or do the levels they give seem to be mediocre? I had a bunch of them advance the kids to level 7 in their master class, and they all lagged statwise behind similarly leveled first gens.
I'm pretty sure it's average stats. With that said, the kids' growths are averaged with their variable parents' growths, so it's not at all unexpected for them to come out mediocre, especially if there's a mismatch in good stats (e.g. Felicia mothering a physical unit).
IMO the real benefit of kids is giving them silly Skills they otherwise couldn't get without a lot of effort (or couldn't at all). Poison Strike+Savage Blow+Draconic Hex Kana was kind of fun.
I've read that the invasions don't scale and you can keep them around until you want to do them, is that true? That would be really convenient later in an emergency if I really need levels.
This is true, but the longer you wait the less experience you'll get from them. It's safer and doesn't really cost much to wait a Chapter after you first unlock the Invasion so that your stats are better. Paralogue 1 is the same.
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@Hikari, for Ch. 13:
Also, making sure this is out there, the Tonics you buy at the Staff Store are amazing. You'll run out of money if you try to stat up everyone on everything but Speed and Defense Tonics in particular can make a huge difference.
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@CF7: If a child unit is an enemy in their paralogue, you can (and have to) kill them and they will join you after the Chapter. (This is not the case with Ally units!)
If you use him, let me know how Kumagera works out. I've never used him and based on stats it looks like he'll get doubled a bunch lategame on Enemy Phase but his Skill set is the stuff of trolling dreams.