As crossovers go, this is a deep dive for Final Fantasy Brave Exvius, but it’s a good one. The cast of the 1998 cult PS1 classic Xenogears has stopped by for a visit, proving that they’re still alive after not being seen for 21 years.

Fei, Elly, Bart, Emeralda and Rico are available this week as new units from featured summons, and you can even get ball of fluff Chu-Chu through a raid summon. You can use them in the Elements’ Formation raid boss battle, which gives you raid coins to exchange for special prizes. And starting April 5, you can challenge the Desert Despair trial boss to earn some really rare stuff.

Beginning today, the hit mobile game FINAL FANTASY BRAVE EXVIUS® unites with classic role-playing game Xenogears® for the very first time in the global version in an exciting limited-time collaboration event. All players can jump in and collect new summonable characters, earn fabulous rewards from a challenging raid boss and more based around the beloved title.

Square makes no mention of how long this crossover will last, but we’re assuming the duration period will be about as long as any other. So if you miss the world of Xenogears (as anybody who played the game does), be sure to log in this coming week. Special login bonuses will be available through the entirety of the event and you will get a free summon for Lapis every day you boot the game up.

Final Fantasy Brave Exvius is available now on mobile devices.