Rating issues
When an attack is carried out, you see a visual marker that it has been executed. Such a marker can be a visual slash across the screen, a red glow, a screen shake, etc. The direct effect to the character is displayed as a numeric value which drains the health bar. The characters themselves flinch, but no real reaction to the violence is shown.
When computer characters are defeated, they disappear into thin air. When you die, your character falls to the ground and you see a message that you are defeated. No injury is shown.
The artwork in the game is slightly disturbing. There are creepy characters and the overall vibe is unsettling. Some cards feature skulls and other scary elements. Some cards feature violent depictions. These depictions are rather cartoon-like and not gruesome and fall within the PEGI 7 criteria.