mtg arena duplicate cards devs have detailed their plans to fix the wildly criticized 5th card problem How Does MTGA Duplicate Protection

The problem was that people treated it like a Pacifism and just assumed it couldn't block, so people were constantly attacking with fliers only to be surprised that Rapunzel was blocking their flier

Shantotto's ability resolves before the spell that caused it to trigger

However, there is more to consider when it comes to how much collectible cards are worth

During upkeep scry X & opponents lose X life where X is the number of Zombies you control

Thanks to the nature of XIV, which kind of encompasses everything, some characters, like Shinryu, were represented by XIV instead of V

It could be a combo that only functions in a vacuum, or some counteracting card interactions