Pointed Discussion

Well to judge this card you first need to take a look at its context: it's a skeleton. Every skeleton is compared to Drudge Skeletons, so just look at it in that light. On the one hand, it's twice the cost; on the other, it's got twice the power. Since it has regenerate the minor toughness difference is fairly inconsequential. Flash is interesting, but only all that useful if you have a lot of responses they you need open mana on your opponents' turns for. It's also quite useful in that it makes for an interesting roundabout removal spell if you cast it blocking a big creature of your opponent's that has little toughness, since you can regenerate it immediately. Rather situational, and not the best if you're going skeleton tribal where you'd be better off with more drudge clones, but it has enough uses for a 4/5 in my book. Actually, if you have Death Baron, or maybe Bad Moon or some other rare boost for skeletons, it could fill a creature removal role quite well. Just make sure, as with any regenerating creature, to leave some open mana; if you don't use regenerate then it's at best a 1.5/5.

I almost went and commented on my comment.
I should pay attention, I'm Zaneshift. XD
Just wanted to add that it's basically a Phyrexian Monitor with Flash rather than 2 toughness, which is a pretty nice tradeoff. Also, Death Baron makes it a "destroy target attacking creature" spell with the deathtouch addition, which is pretty nice.

You forgot the best part, Lim-Dul is the Flavor text!

is more fair of a cost.

Each Time Spiral card was an homage to at least one previously printed card.

This card is referencing the classic Drudge Skeletons and tips a hat to Magic's most famous necromancer, Lim-Dul.

The card is more likely a combination of Lim'Dul's High Guard and Drudge Skeletons. I would take either of those cards over this.

This would be excellent if, instead of Regeneration, it had Fast Regeneration. Name it exactly that, and make the rules reminder text read to do exactly what you want "Fast Regeneration" to do: Be like Regeneration except that you can activate it ''in response'', at instant speed, and it will work like you want it to, rather than the way normal Regeneration works, where you have to activate it before you know what your creature might be getting into. Fast Regeneration to me is in some sense like Double Strike: An ability that should totally be adopted as an Evergreen Keyword, that I designed on the spot in answer to "How do I make this good ability better?" I would be a lot more okay if they brought Shroud back, next to Hexproof. I'm not saying have an overload of Regeneration or Shroud-- I'm saying that some of the cards that would have been Regenerators are now Fast Regenerators and some of the cards that would have been Hexproof now have Shroud- you would end up with a pretty small amount of Double Strike, Hexproof, and Fast Regeneration, and still plenty of First Strike, Shroud, and Regenerate.

@DarthParallax: I don't follow you. Regeneration can already be activated at instant speed "in response" to any spell/ability that would destroy it, or in response to blockers being declared. I can't think of any way to make it "faster" without breaking the existing game mechanics.

What do you mean by "work like you want it to"?

@Darthparallax
What on earth are you talking about?