High power, but I'm on 10/450 (sort of...):
The Wandering Emperor/
Jace, the Mind Sculptor/
Liliana of the Veil/
Chandra, Torch of Defiance/
Garruk Wildspeaker - one for each color that can go in nearly any deck (I have ever had an aggressive enough white deck to not want TWE, but it's rare. I anticipate replacing Chandra someday, but they keep printing
niche red walkers instead of a new generalist.)
Saheeli, Sublime Artisan and
Teferi, Time Raveler -
Third Path Iconoclast and
Repulse effects with some fun interactions. The amount of "fun" will vary with Teferi depending on what side of the table he's on.
Kytheon, Hero of Akros and
Tamiyo, Inquisitive Student - these are only planeswalkers when it's your opponent's fault for not doing something sooner, thus the "sort of" above.
Tyvar, Jubilant Brawler - testing out a pet card to do all the
Insidious Roots nonsense, disregard
The idea of planeswalkers in general is a good one imo, because the "you can attack this
or you can attack your opponent" is a fun minigame in small doses. You could also get this via
Battles, I guess, if you're at that power level. More of the good removal - like
Get Lost or sufficiently ambitious
Prismatic Ending - hits planeswalkers these days, you're not just on
Murderous Rider ripoffs.
You probably do want
Saheeli, Sublime Artisan, though she's not exactly what you asked for. She
can ramp by making her own Servo into a
Worn Powerstone or whatever, though she rarely does so immediately because that requires a curve like
Gingerbrute ->
Mind Stone -> Saheeli. She's also a payoff for ramping out a
Triplicate Titan or whatever by "giving it haste" if you already have a Servo or a
Prismatic Lens.
You
definitely want
Kiora, Behemoth Beckoner. Even without stupid
Nykthos Constructed things, she's [mono-]blue", "works with artifacts", and "ramp payoff for large creatures". Only problem with her is that green drafters might steal her to do the same thing, and that's a good problem to have during the draft portion IMO.
If you don't need
mono-blue,
Teferi, Who Slows the Sunset is worth considering too. I was a skeptic on it in Standard, but untapping a land (let alone a
Lotus Field) plus
The Celestus was enough to keep relevant interaction up. It always played way better than it looked against me... which is good, because it looks like a giant wall of text that says +1: gain 2 life fiddle with game objects, -2: get a card. Also, it comes down at 4 loyalty and the ultimate's only at 7, so it's kind of like
Chandra in that you have to interact with it surprisingly quickly.
