Other known variants
x2Berserk
When you play Feraligatr from your hand, flip a coin. If heads, discard the top 5 cards from your opponent's deck. If tails, discard the top 5 cards from your deck.
ChompFlip a number of coins equal to the number of damage counters on Feraligatr. This attack does 50 damage plus 10 more damage for each heads.
When it bites with its massive and powerful jaws, it shakes its head and savagely tears its victim up.
When using Drampa GX's "Berserk" attack, must ALL Benched Pokemon have at least 1 damage counter or do you only need 1 Benched Pokemon with a damage counter on it to add the +70 damage?
If any of your Benched Pokemon have damage counters it will add the +70 damage. If it required all of them it would have said "all" or "each" in the attack text.