Battle styles aren't a singular mechanic, but more of a label to designate cards that are designed around a similar theme: for example, Single Strike cards are slower and focus on large, direct damage, whereas Single Strike cards are trickier, messing around with your opponent's resources and keeping them on their toes
Specifically the pokeball which is the most obvious difference
Clues then became a major theme of Murders at Karlov Manor , where Clues and investigating show up on a wide range of cards (including artifact lands and equipment that are Clues) and were central to one of the Commander precons, Deep Clue Sea , which is literally described as Clue Tokens / Card Advantage on the box
This card is an SIR from Ascended Heroes, and it depicts Pikachu standing in the woods as sun trickles through the leaves to shine light down onto this adorable Electric-type Pokmon
Some also use shipping labels (with the label peeled off, as a poor mans medium when using the heat pen
The First Expansion - Battle Elite Released on December 16th, Battle Elite (CSM1.5 C) is the expansion to the first set release
