A note on evolving Bluebirds:
As you have a good chance to get Evo'd bluebirds from 50sta version... why would we still want to farm 25sta version?
It requires
44,520xp + 2 blue masks + 1 blue lit
to evo a blue bird.
The 2 blue masks and 1 blue lit will require on average 30 sta to acquire. ( to maximize the sta used for this, saving the other evo materials from the wednesday and friday runs is best )
The 44,520xp will require 24 sta to acquire (2 runs of Oceanus Falls - Great Dragon of the Abyss @ 2x drop rate). This has the added benefit of having chances for +eggs and King Metal Dragons
You will never run out of things to level up, or +eggs to farm. However, waiting for Collab Dungeons to return for skillups is very difficult.
As such, stockpiling the unevo'd drops from the 25sta version and evo'ing when convenient is the better option.
Personally, my current target is to stockpile 60 bluebirds. I have 12 on US side, and 18 on JP side. It does delay my +egg farming a bit, but oh well.
I have started farming up alt accounts to lvl 20 for the +3 egg while my stamina on main account refreshes anyway.