On an uncounterable mass card draw effect like this
Deckbuilding is an important part of any TCG, so once you've tried out these options don't be afraid to make further alterations until the deck feels good to you.
Because Arna is capable of doubling counters, as well as copying auras and equipment, there are numerous interesting directions a deck builder can take
Of course, as Commander grew in popularity, so too did the popularity of prevalence of this monowhite lifegain card that fits perfectly into a lifegain-focused Cat deck, for which there are myriad synergies (many of which can be found here)
Whenever a permanent an opponent controls with a bounty counter on it dies, you gain 3 life and draw a card
There are very few cards currently in Lorcana that interact with your opponents lore count, but the majority are in ruby