Secret Lair is a series of limited-edition mini releases, usually containing a small number of cards with special art, and for Final Fantasy its no different
This can be before blockers are declared, after blockers are declared but before combat damage is dealt, during combat after combat damage is dealt, during the postcombat main phase, during the end step, or, in some unusual cases, during the cleanup step
Building a deck with two Inks that complement each other well and which has a clear gameplan is one of the key elements of not just this, but most, trading card games
Amber/Emerald Aggro sits at 15% share in Core already
The combat damage triggers are what really help myriad shine on this card
One key example of that is the crystals, which were a staple of most of the games' plots in the early era