#replacement effect

It’s mostly just for clarity.

When she was printed, there was a lot of confusion about a couple of corner cases, i.e. what happens when things that aren’t normally creatures would die as creatures and what happens when things that are printed as creatures would leave the battlefield as noncreatures. The printed text made a lot of people think that what was printed on the card leaving the battlefield was what mattered, but that wasn’t the case. Anafenza’s ability, as a replacement effect, has always looked at cards in the zone they’re moving from and not what they would look like in the graveyard, so the change to her oracle text is just to clarify that.The main confusion comes from the fact that “graveyard from anywhere” triggers look at cards as they exist in the graveyard, not in the previous zone.

TL;DR: As printed, Anafenza is worded poorly. She has always worked the same way. If it’s a creature on the battlefield, it’s exiled. If it’s not, then it’s not.

Uba Mask will cause Jace’s controller to exile three cards face up instead of drawing cards. Then, if Jace’s controller has any cards in their actual hand, they’ll have to put two of them back on top of their library.

Not quite, but these cards do combo in a fun way.

When you choose to abandon My Laughter Echoes, its effect will set Plots That Span Centuries into motion a second time. (Its first trigger hasn’t resolved yet, so it doesn’t affect this action.)

Once both triggers from PTSC have resolved, there will be two separate replacement effects looking to affect the next time a scheme would be set in motion.

The next time you would set a scheme into motion, both replacement effects want to modify the event. Applying the first effect will change “set a scheme in motion” into “set three schemes in motion”, which is really just “set a scheme in motion, set a scheme in motion, set a scheme in motion” since setting schemes in motion can only happen one at a time, like drawing cards. The second replacement effect will then replace the first instance of setting a scheme in motion with setting three schemes in motion again. The net result is that you’ll set five schemes in motion at that time.

A static ability is any ability of a permanent that’s not an activated ability or triggered ability. Any ability of a permanent that doesn’t use the stack is a static ability. e.g. Flying