Very isolated curiosity, IIRC, Nicol Bolas fought another planewalker (Leshrac? Or someone else?) in the Time Spiral storu,I haven't been able to read it myself, but how was it depicted? The question I particularly want answeted is how many instancea of planeswalking was Bolas capable of accomplishing during that back-and-forth planeswalker duel? This was before the Mending had taken place, correct?

Immediately prior to the Mending.

Bolas would flit to a world and ambush Leshrac when he arrived, choosing, primarily, worlds that would be distracting upon arrival.

He hit up Ulgrotha, Ravnica, Mercadia, and Kamigawa.

So Bolas has demonstrated the capacity to planeswalk to/from a minimum of 5 times in a matter of a few minutes with energy to spare, but pre-mending? Just overall curious how planeswalk does and doesn't work in the context of current planeswalkers (even if they were pre-mending) like how frequently they can do it, what prevents them from doing it, what they need in terms of mana or concentration, etc.

Agents of Artifice and The Purifying Fire both made it clear that planeswalking, aside from the first time which is triggered by great stress or trauma,, requires great concentration and much preparation, and is exhausting. But I suspect that that is being forgotten or ignored, and they are gonna go with 'you can planeswalk during moments of great stress and trauma, like a battle against Bolas'.

Depending on how it unfolds, it could just be a distinction between "Planeswalking" and "Planeswalking to ___". Maybe they just pull the trigger to anywhere out of fear, and it's choosing the specific destination that requires most of the effort.
Although one would imagine such a wild attempt would most often result in disaster, whether you planeswalk into the stratosphere, into a solid object, or just to one of realistically numerous immediately inhospitable planes.

Which is why it would be a last ditch effort. When a 5% chance to live is better than a 100% chance of death.

No, it's made pretty clear that the hard part is leaving the world. Destinations come once you're already in the eternities.

Of course, the purifying fire also showed that planeswalking under duress is possible, but it's a baaaaaad idea.

I got the impression that Gideon was doing it every 12 hours with no sleep between Zendikar and Ravnica while doing major battling on both. Though I have a feeling they leave it up to the author on how hard or easy it needs to be depending on the story.

I'm seriously waiting on how this is going to be written for our olde poster boy Jace Beleren, to be able to frikkin Planeswalk while catatonic, in post-Mending times?

Blessed Serra... Dyfed and Feroz must be rolling in the Blind Eternities at the moment. Dat Plot Armour too stronk!

Well the Plane Shift for Amonkhet tackles rpg rules for planeswalking, including walking under duress. And basically they say it's possbile, almost reflexive and similar to a spark igniting/first walk and the walker is just kind of flung across the eternities.

We're talking about the same character who, in preparation for fighting Emrakul, cast a spell on his own brain that in case of sudden mental meltdown, would automatically link him to his fellow Gatewatchers, lock them behind the strongest mental defenses he had, and would throw in an imaginary mental duplicate allowing Jace to interrogate himself as to his own level of sanity. He definitely has some kind of ABORTABORTABORT mental-crash auto-planeswalking fail-safe.

Now let's see if the Story team actually writes that explanation.

(And then I got ninja-ed.)

Or they could just do this. That works too.

Of course, yes, I was primarily asking so as to come up with a creature feature for planeswalking, starting with Planeswalk (1/Day) then realized maybe characters like Bolas, Garruk, Vronos, etc could have focused their planeswalking to be able to do 2-3 times a day, then realized that Gideon wasn't just planeswalking 1-2/Day, but 1-2/Day without even a Short Rest.

Then PS: AKH came out.... then I realized what James Wyatt meant by "takes about a minute... cast like a ritual", for planeswalking outside of battle (or attempting during battle) that it is essentially a non-existent spell that the core rules clarify would take 1 minute, not 1 standard action, with the rider that the walker character must maintain concentration during the "casting time" or else have to start over again, but keep the spell slot (if it were a real spell)

The planeswalking under duress thing is much more straightforward.