Going in order…
Xainfried is all about spamming Shapeshift for maximum damage. He has a Spiral, which means he gets a tad stronger than most Water Lances, and got buffs like Frostbite Infliction and Shapeshift Prep on his skills. I use him a lot for some of the Dragon Battle stuff in his element but not much outside of that.
Yurius is also Shapeshift heavy but he goes for an enhanced version of himself rather than a Shapeshift to a Super Armor DPS Truck. He loses out on Dragon Tanking but that sort of strat hasn’t been working as of late, so having enhanced versions of his usual rotations helps. The new Nihility content invalidating units like Pipple also helps him shine a tad more by comparison.
Last I heard, Albert is quite strong for most endgame content for Light. He made the transition to the Lilith fight pretty cleanly, though Gala Euden exists and has an easier time against her with his recent spiral.
I would see what their kit is before you grab them (they should allow you to preview them before deciding on who to get), but you can take your time if you’re not sure.