Abilities » Shell Survival
There’s a new deck building rule with Shedinja from Vivid Voltage. Shedinja with the “Shell Survival” Ability cannot be the only Basic Pokemon in your deck. You must have at least 1 other Basic Pokemon in your deck besides Shedinja with “Shell Survival”.
Source: Vivid Voltage FAQ (2020-10-31), TPCi Rules Team (2020-11-12)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH4_66
SWSH4_66