Some players argue that this is a cool thing, while others say that even though its within the rules, having access to all colors is against the spirit of the format
Both of these place hit counters on anything that dies, so Etrata becomes very likely to one-shot whoever she attacks for the rest of the game
however, she is not cruel or violent
Ayli, Eternal Pilgrim: These two legendary creatures seem like they might justify an archetype by themselves (as long as they get to bring Lingering Souls with them, as part of by themselves)
Assuming you can use the trigger on the turn you play it, you get a 5/5 demon with lifelink and haste right away
Players are rarely willing to decline its draw ability, fearing they'll fall behind