I'm debating whether I should feed Senko to get Ursula or Hibari to AW99. On one hand, Ursula seems to be a good replacement for Nanaly with her 10% assassination proc paired with triple shot plus reduced attack animation and her S.AW is basically attack multiplier with triple shot for 3 enemies in range, but loses assassination. Her AW passive can also stack with Spica's to boost archer's attack. On the other hand, Hibari is, from what I heard, Anya with physical attack, though her S.AW is a more improved version of her normal skill and way longer CD. Not worth S.AWing her imo. Between these two, I'm not sure who needs Senko more in the long term as both seems very good. With that said, both saved my arse today when I got my revenge victory for the two 4* challenges I've been stuck on for a long time.
Edit: Not sure if Sukuha or Louise would have done it, but I finally 3* all the Eastern maps with Hibari. Magic City will have to wait since I need to raise my gold enchanter to have Hibari dealing any damage to the golems. Still not ready for those mithril golems though.
Edit 2: Correct me if I'm wrong, but is the collab unit for Aigis that Neuschwanstein Castle girl from Shiropro's current gacha? I know that we get Senko for map reward in Aigis and Fragarach for map reward in Shiropro.