Titania has the ability to swarm enemies with killer butterflies, and she herself can transform into a killer fairy. She seems inspired by the likes of Pan’s Labyrinth more than a Disney movie. In addition to those abilities, Titania can also gain a buff by extracting it from an enemy, and lift enemies into the air, disarming them in the process.
The patch also adds an assortment of other stuff, including the titular new quest, The Silver Grove. Plus new operator suits, new weapons, and some new additions to the game’s PvP modes.
The game’s fusion system, the way in which mods are upgraded, also saw a revamp, simplifying the process. Instead of fusing unwanted mods into other mods, you “disenchant” those mods for a new resource, Endo, and use that to upgrade mods. That’ll help to clean up everyone’s mod inventory, and keep you from wasting potential mod upgrade choice by undergoing poor fusions.
The best addition, though, is easily the ability to “spray” the environment with Glyphs.
If you wanna check out the full patch notes, in detail, you can head on over to the Warframe forums.