some thoughts on using the new Elise,
using her effectively means your team quite revolves around her. You have Elise herself, and then the second unit who gets her out of harm's way. Most of the time you want draw back since reposition can be restrictive since she's a horse. The times you want reposition are when you use her to attack a ranged physical unit. If you draw her back against these units (bows, daggers), then she will certainly die in the enemy phase. To be efficient, some kind of distant counter reposition unit would probably be best to get in some damage against them.
Brave Lyn is an issue. If you don't pin her down with gravity, then she'll be all too ready to kill Elise or someone else in your team. She's also unaffected by distant counter so that's a problem too. You need a unit that can successfully bait and kill her asap. Reinhardt isn't an issue, Elise can take him just fine.
Elise is your floodgate, if she doesn't hold the enemy back then you'll be pressed back into uncomfortable positions. But she's also very frail, so you want to bait out units she can't deal with (mostly Brave Lyn and some other physical ranged units) and get them killed quickly. I think a solution is to use either FCorrin or ATiki for their physical bulk (although you'll have to jump through some hoops to try kill BLyn in one round) and have them be the Reposition unit of the two. Alternatively, the new Takumi has the grimoire effect built in so he might be even better since he can get Elise around tight corners by warping in whichever direction you need to pull her towards.
It still isn't really safe to jump in to get a kill since just because they can't move doesn't make the enemy units any less dangerous. But one of your units is tied to Elise leaving you with only two units to use. I think at least one flier is good since you can use them more flexibly to get Elise out of tight terrain spots, this one being your draw back unit. Having these two extras being offensive makes the fight go quicker, but enemy phase builds might be safer.
Infantry teams are a joke, Elise alone can take them with someone pulling her out of the way. Adding a dancer complicates things, but still not bad. As usual, cavalry makes life difficult, you need a BLyn counter.
Colorwise, you probably won't need any red units since there aren't any green threats that Elise can't handle. Hector is slow, Brave Ike is an infantry, and the other green threats are all mages which Elise can handle. Colorless units I think are a big problem you'll face, you need a way to deal with those physical range 2 units. And again, you need a way to handle BLyn safely. And I think honestly as long as you can get rid of her, the rest of your team only make the fight go faster. So bring whoever along as long as you have a plan for BLyn.
tl;dr BLyn is still a problem.