Official art for Buck: Legacy card game, illustrated by Petirep. This illustration depicts a pegasus fighting an off-screen enemy with tentacles (possibly an Aqua type ‘Tentacle Monster’ from the core set), this is a promotional card for an unnamed project that was quietly put on hiatus in favour of LuGame and Immortal Emperor game projects.  
The card has the designation PRO-008 and while copies do exist, they have never been formally distributed.
 
The project was called MAXHEART, and it was the precursor to Immortal Emperor. A video exists on YouTube depicting early gameplay footage.  
The game was about collecting gun-wielding maids to fight an army of cute androids who also had guns.  
MAXHEART would be re-skinned to become a game about powerful mages fighting otherworldly creatures.
 
The promo card is likely to be given away as part of another event.
 
Official Buck: Legacy Website  
Official Buck: Legacy Twitter  
Artist’s Twitter  
Developer’s Twitter