So effects that target all characters or all of a type of card should still work unless they have choose in the text
Abilities that affect multiple players are resolved in the same way - starting with the player whose turn it is, each player takes the required action, and then passes to the left
[[Sephiroth, Fabled SOLDIER]] turns into [[Sephiroth, One-Winged Angel]], granting: Super Nova As this creature transforms into Sephiroth, One-Winged Angel, you get an emblem with Whenever a creature dies, target opponent loses 1 life and you gain 1 life. Whenever Sephiroth attacks, you may sacrifice any number of other creatures
Now, with Disney Lorcanas Ursulas Return marking the fourth expansion set to be announced, players can expect the gameplay and mechanics to develop in even more exciting ways