Beholder: minion aberration reads:
Whenever you purchase or use a basic action die, deal 1 to target opponent or creature.
Global: Pay 1 energy. Move a die showing an action face from your reserve to your prep area. Do not roll it next turn.
What does exactly means "use a basic action die"? Is it to roll it, to use any of the burst action, to use the energy it provides (it rolled that way) or both of the former?
To “use a basic action die” means to use that basic action die’s ability after rolling an action (i.e., non-energy) face on the die.
The relevant text from the rulebook is as follows:
DC Dice Masters: Justice League Rulebook Page 25:
While you can use heroes and villains together, or characters from different teams, you can’t use two cards with the same name (even if they have different subtitles).
-The Dice Masters Rules Team