Not only does Lightning have some incredible innate abilities like Lifelink and First Strike, but when paired with the right support cards, she can really make the most of her double damage potential to devastating effect
When Zodiark is summoned, each player sacrifices half their creatures (rounded down), and for every being sacrificed in this way, Zodiark gets a +1/+1 counter
A two mana 2/1 with flying on your turn is a solid aggro play, and this has a ton of upside beyond that since you get two permanents
Youre looking for the Goblin Battle Jesters, Zuko, Avatar Hunter, and The Fire Crystals of the world
It isn't even that this version is much more valuable than non-Lord of the Rings ones
Add to that plenty of ways to put additional +1/+1 counters on it and many smaller synergies throughout the Standard format, and I expect Walking Ballista to be a Standard Staple from the start