It's no wonder that Cygames can give away freebies.
It's a mandatory purchase at this point.

They're not making it easy on people this month. They've cleverly guaranteed more than 1/3rd of a spark during the bonus gala, but they're introducing premium limited units for the regular gala. We can wait til summer to spark for Andira, but it won't be at a discount. Veteran players may favor chasing the new units, but newer ones will have to choose between broadening their collection of limited units...and getting powerful grand weapons and units, and the Zodiacs at the end of the month.

Cygames is diabolical. Gives you a taste, but still makes you pick your poison.