Garon is my favorite in terms of art design. Soeda Ippei's work is an absolute top in FEH and Garon's dragon form is arguably the most badass that is in the game. Sure, the Grima summon is also cool, but Garon has the plague dragon with the weird spaceball head...that's a win in my book.
Well there's multiple ways to answer this. Favorite personality wise? Unit wise? Design wise? Etc.
I'll assume you mean Unit and Design wise.
For me unit wise it's probably Tiki and Grima (Both Male and Female) as they're pretty freaking fantastic units when built right. Male Grima for instance murders pretty much anything except for the Falchion brigade and a few speedy sword units like Ayra, Karla, Etc. Not to mention for Grima I love corrupted units (my arena team is all fallen heroes) and with design, probably Myrrh because she's so damn cute; plus she's a great unit as well. But then Garon happened. OH YES.
If we are talking personality it would be a tie between Ninian, Tiki and Corrin. If we are talking about a bit of intrest in the character and want to know more about what he/she is like I would say Female Grima. She is corrupted, but is there any robin in there at all? Is she actually female or is the Grima insdie her male and the body is just female?
Both Grimas because I love their character and voice acting. I'm also partial to any sort of "fallen" or corrupted fire emblem character. Second would probably be Nowi due to her strength and ease of attainability and third would be Myrrh because shes super good and cute but I don't have her.
Bridal Ninian, if she counts. Easily. =w=
If we're talking about straight-up Dragonstone units, easily Halloween Myrrh or Grima. Both Grimas are just equally awesome designs and have such good lines. Halloween Myrrh just has cuteness that can end all violence in the universe except that she's such high BST that she's what's causing the violence.
From a combat standpoint: L.Tiki incontestably. Whether it's tanks or squishy units, my preference is fast over slow (maybe tanks especially, actually, since squishy units usually have high atk so they can just stick to hitting first and not getting hit). Also, I'm not entirely sure why but I tend to prefer blue for a defensive colour. I feel more comfortable in blue than I do in red. Maybe it's just that Nowi is the best tank I've ever had and the one I've invested most in. After L.Tiki, it's a blur. H.Myrrh I like, especially the special fighter + QR build, yikes. Myrrh I like because she has a forced undouble. Nowi and Fae I like because they can be fairly fast and have mixed bulk.
As a story character: A.Tiki. I never cease to be amazed at her insistence on pursuing attachment and appreciating its value despite more loss than I would know in a lifetime. Mind you, she's a fictional character, so I'd like to know if there are people in the world who are genuinely like that. Also, the voice acting is lovely.
Ninian is pretty good too, but my knowledge of her is much, much less. But I like quiet characters.
For looks in dragon form: don't have one I like better than Fae. Also, rawr rawr :D
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