Touhou Puppet Dance Performance: Shard of Dreams - What Winter Left Behind Letty
Surprisingly enough, Letty is one of the tougher fights in the game, having a full team and everything. Frustratingly enough, all of her Puppets also have Dream Shards, an accessory that's supposed to be exclusive to your starter Puppet that increases all of their stats by a bit.
Extra Eiki (Warped/Void) is a pretty bulky Puppet, with 140 HP and 100 in both defenses. She also has the Pretense skill, which changes her type to become Fighting, as her first skill is Fighting type. Besides that, she's not too gimmicky.
Power Yuuka (Nature/Electric) is strong on the Focus side while being slow and having frail Sp. Defense. She tends to alternate between using Thor's Hammer (a strong Electric type skill with recoil) and Power Drain (a Nature type skill that restores damage dealt as HP), unless your Puppet resists either of those.
Power Lily (Nature/Void) may have a low BST, but she's surprisingly strong to make up for it, having powerful Spread skills like Danmaku Dance (Void), Thunder Force (Electric), and Pollen Mist (Grass). She's not very bulky though, and she can be outsped with ease.
Speed Shizuha and Power Minoriko (Nature) are both about what you'd expect from pure Nature type Puppets of those styles: Speed Shizuha is fast but not very strong and Power Minoriko is strong but not very bulky or fast. Just don't switch in any Nature-weak Puppets and you'll be golden.
Power Letty (Water) has the pesky ability Force of Nature, which nullifies her Nature weakness and even increases Sp. Attack if she's hit by a Nature skill. Other than that she has high HP and Sp. Attack/Defense, but not much else.