They look pretty good, don't they? I may swap out a few skills for something better down the road, as Glimmer isn't all that good of a special and Anna could use something better than her native Spur Res--but that's low priority.
Sharena is the first of the trio I promoted to 5*, and she's been quite a useful lancer ever since. For awhile, I used her with Quick Riposte 1 and her native Spd +3, but she really works a lot better with Fury 3. She's strong, pretty bulky and quick, and the setup I have let's her perform support functions really well too.
Anna, my second Askr promotion, is both fast and powerful. With 41 spd, she pretty much doubles everything, which is great for Desperation. Fury 3 has great synergy with both Desperation and Noatun, which has a built-in Escape Route 2. I especially liked that setup in the Tempest Trials, where she would reach 1 HP, and be able to warp all over the map and quickly deliver her Reprisal special.
And, last (and probably least), Alfonse. He's quite strong, but his slowness is certainly an issue. He'll be doubled by most things. However, he has a really nice Atk, and reasonably nice bulk. I went with a Brash Assault build, which synergizes with his weapon, which has built in Defiant Atk 2. If he's under 50% HP, he will have 62 Atk on the offense, and, with his respectable bulk, Brash Assault works well to allow him to wipe out most things if he can survive the counter. I might give him Armored Blow or Defiant Def later on, but this is good for now.