She can be a brat at the beginning, but during her support conversations, she can actually be pretty nice and sweet, especially during the ones with Lissa. She actually has pretty good character development, too. Besides that, I just like how she's such a grammar/speech Nazi and really cares about education. Kind of reminds me of myself.
Have you tried reclassing your level 20's? And I'd get Panne and Vaike to an S support and level them both up. Panna can be a very powerful unit I'm sure Vaike can too, I've just never tried with him. I would reclass Henry to a sorcerer and Lon'qu to a swordmaster with a master seal and once they are reclassed keep leveling them from there. Have you reclassed Chrom as a Great Lord? If not. DO THAT. Chrom is a BOSS when he's a Great Lord, same goes for Lucina. She makes for a good Great Lord too. Paired up with Owain they would make an unstoppable pair, I have found.
S supports and the pair up system are your friends. Use them to get ungodly bonuses. I would suggest pairing up people that can get an S support. These unlock more paralogues where you find more children units and get more exp for your units.
I once again stress S supports. In case I haven't stressed it enough XD. Anyways, if you need anymore help I would ask Ventus as well. I believe he's played the game on lunatic mode. Anyone whose played that mode and lived to tell the tale is cool in my book XD. You can also keep asking me questions, too.
Ah, yes. THAAAAT chapter. If you think that one's tough, you're gonna have a rough time with the final chapter. heh. Anyways, do you have any people up to an S Support? If so, bring them and some strong weapons and pair them up. Make sure you bring your strongest people too, in case that wasn't obvious. I would probably on the Risen that don't have ranged weapons I would take them out with ranged first off to save your units from a bit of damage. If you still cannot pass the stage I would advise exiting the map and training your units up with reeking boxes. Hope this helps a little.
Henry, I would agree, is one of my favorite mages. But personally, I use all the mages, except Miriel I can't stand her for some reason. But once again, it just depends on the playing style of the person.
Yes, that would happen to be Tharja from FE13. And I disagree, it just depends on your style of playing Fire Emblem. If you asked me who the most useless character in that game is I would say Virion. But that's just my opinion. Tharja is one of my best units. But that's just how I play Fire Emblem. But, on that note, I'm glad to see another Fire Emblem player on ZD. ^^
Inexorable Death? Hmm...let's see. My units at that time were Lucina (Great Lord), Chrom (Great Lord), Lissa (Valkyrie reclassed from Sage), Donnel (Hero), Olivia (Swordmaster; reclass her from Dancer to Myrmidon then promote), Vaike (Warrior), Sumia (Dark Flier), Morgan (Grandmaster), Avatar (Sorcerer, reclass from Tactician to Dark Mage then promote), Severa (Hero)
What I did was send Chrom and Lucina out to rush the foes (pair Chrom with Lucina); Lucina has Galeforce so if she kills one foe she gets to act once more on that turn. I just did that while keeping Lissa and the rest of them safe.