Here are some Genshin Impact-inspired name suggestions for siblings, considering Lyney, Lynette (twins), and Freminet (youngest male):

Maintaining a Similar Aesthetic (Lyney/Lynette Style):

• For a Sister: Layla (similar sound and feel, slightly softer), Lyra (musical connection, celestial theme), Lumina (light-related, echoing Lynette's magical nature).
• For a Brother (older or younger than Freminet): Leon (strong, similar initial sound), Linus (gentle, slightly different sound), Lysander (more elaborate, Greek origin).

Expanding the Theme (Genshin Impact Elements & Lore):

• Water Element: Oceanus (masculine, powerful), Coralia (feminine, delicate), Thalassa (feminine, sea-related).
• Pyro Element (like Lyney/Lynette): Ignis (masculine, fiery), Ember (feminine, warm), Phoenix (unisex, legendary bird).
• Cryo Element (like Freminet): Glacius (masculine, icy), Rime (feminine, frosty), Avalanche (unisex, powerful).
• Anemo Element: Zephyr (masculine, breezy), Aura (feminine, ethereal), Gale (unisex, strong wind).
• Geo Element: Titan (masculine, strong), Terra (feminine, earth-related), Stone (unisex, solid).
• Electro Element: Sparky (masculine, playful), Volt (feminine, energetic), Static (unisex, electric).
• Dendro Element: Verdant (masculine, green), Flora (feminine, plant-related), Bloom (unisex, growth).

Names Inspired by Genshin Impact Locations/Characters:

• Mondstadt Inspired: Aether (masculine, ethereal), Lumine (feminine, light), Venti (masculine, wind).
• Liyue Inspired: Ningguang (feminine, elegant), Zhongli (masculine, wise), Xiao (masculine, mysterious).
• Inazuma Inspired: Raiden (masculine, powerful), Yae (feminine, cunning), Kazuha (masculine, graceful).
• Sumeru Inspired: Cyno (masculine, sharp), Nilou (feminine, graceful), Tighnari (masculine, wise).

Considerations:

• Flow: Consider how the names sound together. Do they flow well when said aloud?
• Meaning: Research the meanings of the names to ensure they align with your desired image.
• Popularity: Check the popularity of the names to avoid overly common or uncommon choices.
• Initials: Consider the initials of the names and how they might look together.

Remember to choose names that you and your family love and that resonate with the Genshin Impact theme while fitting the personalities you envision for the characters. This list provides a starting point for brainstorming; feel free to mix and match elements from different categories to create unique and fitting names.