New Skin Lines (or expanding current ones)

Lunar/Solar Eclipse (Diana would fit in here somewhere) Harmonic Convergence (two alike champions or two opposite champions) Battle Boss and Arcade expansion Light Seeker (dealing with those who have lost someone in lore, e.g. Yasuo and Lucian) Parliament series (pertaining to champions with time or scientist lore, e.g. Ekko and Mundo) Galactic Empire series expansion Hextech expansion Time Displacement Void Hero

Just stuff off the top of my head, really like the Eclipse.