G-Corsola is now only available from the gifts you can exchange with Matteo at the end of a Route once a day. Those gifts (if space) gives an egg 2/3 times. The egg pool has 1/7 to hatch a Corsola. 27 trades on average to get <150 rank. This way it takes 300 days on average to get a good Corsola

The battles from Dezzz's OGL tournament are some off the best I've seen in a while