I originally posted this to the mtgfinance Reddit, because I think it's one of the better places for MTG discussion in general. The force is less populated, but probably the best. I'll part it here too.

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I was looking at the WAR card file yesterday and noticed a pattern. Planeswalkers in WAR that cost four or less don't really have ultimates. The closest are Jace and Chandra, but they are not really as game breaking as what we are used to. In fact, all CMC <= 4 planeswalkers hardly generate much threat at all on their own. The only real exception is Gideon, who is a mythic. Planeswalkers that cost five or more (rares and mythics) tend to both produce threats and have an ultimate.

Why do I think this is relevant? It could represent a change in planeswalker design philosophy. If we see rare and uncommon planeswalkers in future sets, I'm pretty sure these maxims will hold. For mythics, it could be that you need to play at least five to get a game breaking ultimate to threaten.

What does this mean? Four is pretty much the cutoff for playable spells in eternal formats (barring ramp and cost cheating decks). Teferi is the exception, because he 'costs three.' The days of compact win conditions at three or four mana may be over. Jace is obviously the high water mark, but Liliana the last hope could play that strategy at the three spot.

I've run new Teferi and Narset in legacy and they're great. What they don't do is apply any real pressure. I'd put them in the same league as back to basics or search for Azcanta. Your deck still needs a card that wins.

Why is this financially relevant? If my theory is correct, we may already have the best eternal planeswalkers as far as compact win conditions go. Jace and Liliana are already pricey. There's a good chance Jace never becomes obsolete, but this new design philosophy would cinch that.

On another note, I also think we may have seen the most powerful iterations of the 'only value, not threat' planeswalkers in baby Teferi and Narset. WOTC tends to overshoot on their first go round. The fact that these cards are in the same discussion as back to basics is telling.

It's no secret that WOTC is making another shift in design philosophy in general (with the focus on the play test team). With WAR I believe we are some hints as to how they will handle the flashiest card type in the future.