Make your own Magic card!

1. You shouldn't have to pay 10 life for anything that isn't a bomb. I think having to find a way to sacrifice him is enough for a cheap Planeswalker; maybe add "you may pay B (or something). If you do, return ~ to the battlefield and flip it" if you want.
2. Planeswalker abilities work at sorcery speed; the only way to get the +1 ability to do anything is activate it during your main phase and then attack with whatever you targeted (or make it fight something that'd otherwise kill it, but yeah); you can't activate it in response, but somebody can aim a killcard at the creature in response to the ability, and the regeneration won't happen.
3. I'm not sure you can sacrifice cards; you can sacrifice permanents, though. Also, kind of OP.

Just go on Gatherer, go on Advanced Search, and put Planeswalker into the Type box; it'll give you some examples to work from. You can also specify color or "put a creature token" or "regenerate" or whatnot.

Not sure how to cost it, but my best shot is-

Refuge Among the Dead 2[W/B][W/B]

Instant

Destroy all creatures you control. Return them to the battlefield under your control at the start of your next upkeep.

Essentially it's to let your creatures dodge a board wipe at the cost of given them summoning sickness.

edited 24th Oct '14 12:16:21 PM by BigMadDraco

Life-Death Balance - WB
Enchantment
All creatures have lifelink.
You cannot take without giving. You cannot give without taking.

Le sigh. Okay...

5 seems to be a pretty typical CMC for black planeswalkers, and the life/mana exchange rate is about 2:1 based on Phyrexian mana. I'll also assume setting up the sacrifice costs 2, like you said earlier.

Also, because I realised this would make an amusing card on its own:

edited 24th Oct '14 1:04:35 PM by Noaqiyeum

Eternal Martyr WW

Creature- Human Martyr

Undying

Counters can not be placed on ~.

W Sacrifice Eternal Martyr

"My greatest pride is that I have more than one life to give for my country."

1/1

edited 24th Oct '14 12:55:28 PM by BigMadDraco

Soulstealer Ghast - 6B
Creature - Demon Spirit
Whenever ~ deals combat damage, its owner gains three times that much life.
2/3
It has been harvesting souls for so long it forgot why it started taking them in the first place.

edited 24th Oct '14 1:20:56 PM by kagescorpionakki

Multiple instances of lifelink are redundant; you're gonna have to word it out. :/

x3 I can see Hired Victim as a one-drop. I think; black's not my primary color. :| Actually nevermind, two's good.

EDIT: Planeswalker guy is okay now.

edited 24th Oct '14 1:17:09 PM by Knowlessman

Did not realize that rule had changed. Hopefully the new wording makes sense. Also gave it a neat spin where stealing it is mostly pointless.

Hurrah! Thank you for your help.

Revisiting a reference from earlier in this thread:

Dafuq is that supposed to be. Did RoboMaRo come up with that?

(Can't think of a frigging name) 5
Enchantment Artifact
~ enters the battlefield with 7 proxy counters on it.
Remove a proxy counter from ~: You gain protection from target spell or ability targeting you until end of turn unless its controller pays 1. (You may activate this ability multiple times targeting the same spell or ability.)
"Yeah, good luck with that."

EDIT: Dammit. Good thing I didn't make it cost 7. :|

edited 24th Oct '14 3:10:40 PM by Knowlessman

Witchbane Orb completely blows that one out of the water.

Adaptive Reptile - 4UUG
Creature - Lizard
After a spell or ability resolves targeting ~, ~ gains protection from sources with that name. (This effect lasts indefinitely)
1G: Regenerate ~.
5/5
Nothing ever works twice.

That's based off that one SCP, right?

Yep. 682, to be specific. Not sure if he'd also be black, or if I should've worked in something anti-human or something.

Nuclear Power Plant - 3
{T}: Add {3} to your mana pool.
When ~ is put into a graveyard from the battlefield, put 2 -1/-1 counters on all creatures you control.
As long as ~ is in the graveyard, each non-Zombie, non-Skeleton creature you cast enters the battlefield with a -1/-1 counter on it.

edited 24th Oct '14 5:12:43 PM by kagescorpionakki

Makes creatures with Undying nigh-indestructible. But only nigh, because they still have to visit the graveyard, and then they come back with jet lag. But still, undying.

And then there's this guy.

Fixed it so it only applies to things you cast from your hand. Which fits with the whole 'dead things aren't affected by radiation poisoning' schtick.

Harmony Jewel - 0
Artifact
{T}:Add one mana of any color to your mana pool. Target opponent gains control of ~ and untaps it.
Sharing is caring.

edited 24th Oct '14 5:21:52 PM by kagescorpionakki

Those need to happen the other way around: "Target opponent gains control of ~ and untaps it."

Arthur Dent.

Then why not name him? :/ This thread is littered with legendary creatures, anyhow.

Rust Monster (G/R)(G/R)
Creature - Insect (Close enough, right?)
Whenever Rust Monster deals damage to a creature, destroy all Equipment attached to that creature.
Any damage Rust Monster deals to an artifact creature is enough to destroy it.
Whenever Rust Monster deals combat damage to a player, destroy target unattached noncreature artifact that player controls.
1/2

Agony Brute (1RR)
Creature - Ogre Warrior
2/2
Whenever ~ is dealt damage, it gets +2/+0 until end of turn.
R: ~ deals 1 damage to itself.

Does getting a +1/+1 counter remove an existing -1/-1 counter? Because I'd always assumed that they were tracked separately.

Opposite counters do indeed remove each other.