the ability checks for any artifact you control, not the one this Aura is attached to
While it's hard to tell what Katara, The Fearless does at first glance without its ability text, she's a 3/3 legendary creature that duplicates the number of triggers Ally cards you control create, allowing for a cascade of abilities during a match
The borderless version is already pretty pricely, so I think theres more value to be gained in the regular copies, but if you have the ability, Cloud holding his sword is always going to be a big draw
One of the most popular cards to include in an infect deck, especially ones featuring green, is Vorinclex, Monstrous Raider because it doubles the number of any type of counters placed on a permanent or a player
Im not holding any copies of these cards, aside from some for Commander decks, so if Im double-pumping, its out of forgetfulness and not out of nefarious planning
Tap 2 black and 4 colorless to do 10 damage to each opponent with no cards in hand