Nicely summarised and explained by Haruno over at the GuardianCross-Forum.com. It arrived in Japan version in their recent 1.3 update. It should be our 1.2 update.
My thoughts on it:
- It now takes 2 copies of a guardian and 170-190 levels (4*/5*) to max a guardian because you are essentially training 3 guardians to max 1.
- It will discourage trading to some extent as now we want to keep our extra cards.
- The new types are potentially better than Ace as I think Guardians are classified into 3 main types: Speedster, Tanker, Magic Nuker. Agility, HP and Intelligent could be the most important stat and the 15% increase in those areas could be the deciding factors in battles. It is also statistically harder to get 2 of the same guardian to rebirth compared to rebirthing an Ace with any other type.
iTunes App Store link: Guardian Cross - SQUARE ENIX