I broke out some of my oldest cards to see what these borders used to look like: Harbor Guardian from October 1996s Mirage , and Vodalian Zombie from Invasion , released in October 2000
While the lawsuit goes to great lengths to show the ways in which Lorcana resembles the as-yet-unreleased Upper Deck title, game mechanics, generally, are not protectable by copyright law
Whenever this creature attacks, put a +1/+1 counter on it
Beyond that there is how immediate the life gain is, how much you get or can potentially get, how cheap the card or effect is and how hard it is to disrupt
I can really see this card being a real all-star in a deck like Isshin, Two Heavens as One because you can get two triggers and choose different modes or double up on the same one depending on what you need
When you're following the instructions from the first mode, first the player whose turn it is chooses which creature they're going to sacrifice, then each other player in turn order does the same