I actually nerfed Siofra a bit after launch. She hasn't gotten any buffs since then. She's probably the first somewhat tough fight in the game though - intentionally, as a self-proclaimed gatekeeper. The main flow of the fight is to kill her summons ASAP, try to go into third phase at high health, and then burst her down before she bursts you down.
Metatron, Celica, and Sarah are maybe the most versatile allies available at the time, with decent survivability/buffs and heals. Maya, unfortunately, doesn't do very well against her.
If all goes well, 0.32 tomorrow! If not, I'll just enjoy the mental breakdown and keep working lol.