Ok so I’ll copy some advice I gave someone in a PM a long time ago. Should still apply. Although the pic of mine is outdated.
Hey! I don’t mind at all! I’ll show you mine for reference.
I have no idea on how to build her.
In general Eirika prefers to be on teams that have a lot of visible buffs going on thanks to her refine. It copies the buffs allies have to her during combat. So mixed teams that run tactics skills work well. Her base kit also works well for this with Siegelinde having hone attack built in and her having hone speed 3 as her C.
That can really depend on the build and how much you’re willing to invest in her. As you can see with mine, she has 42 speed without the boon. If we removed the summoner support that would be 40 with 5 dragon flowers. 40 speed is still pretty good these days, and speed can be quite easy to buff, especially with her weapon being the way it is. With just her base hone speed 3 she can bump it up to 44 if she buffs an ally. With joint hone speed she buffs both her and allies for +5 speed, which is even better. Of course that skill is quite rare. Odd speed wave is a cheap alternative from a 4 star H!Rolf but of course isn’t as consistent.
Now with a speed boon that would leave her attack at 47 without summoner support in my build above. Like speed it isn’t too difficult to buff her attack (especially with her weapon) but 47 base isn’t all that high. So I do think that +attack is ultimately better. After all it won’t matter that you double your opponent if you don’t do any damage to them.
Yes. Really DC can be good on most units, but she has decent mixed bulk so she won’t be as weak to mages like a lot of other similar units.
Now this was certainly quite a bit, but I do hope that it helps. If you have more questions about her I’m happy to help if I can. Someone_Person also has a good Eirika and could probably give some advice too.
Now what can I say now compared to then? Eh probably not much. The usual skills are good on her with some investment, DC, DR skills, etc. She does prefer visible buffs instead of in combat due to her weapon. And with L!Eliwood she can stack some buffs really well if you set stuff up right. I’ll also show how I run her now. Not that different from the old pic, but a little bit.
Well she’ll need R duel infantry if you want her to score as best as she can. And honestly we have other sword infantry who can score better without needing duel skills, so even I’ve dropped her in arena now. But she can still be very good as a buffer, especially if you like blade tomes.