Yikes! I don't think Avatar of Woe / Visara the Dreadful should cost 4 mana, even with a 1 mana activation cost.

It omits the anti regeneration clause but.. yeah; give it SOME kind of limit. Royal Assassin at least can only kill things that are made vulnerable.

­Visara the Dreadful is a 5/5 mono-colored flyer for just two more mana.

Basilisks don't have the anti regeneration clause. So I didn't add it here. I don't mind it not being there. This is basically just saving you from attaching Viridian Longbow to a deathtouch creature.

Visara is also a mythic legend who got reprinted in the From the Vault set of the most iconic / desired legends of all time! And the P/T is utterly irrelevant to the gameplay consequences of this being on the board. I hope you wouldn't try to print a two-drop with this ability and justify it by being 0/1.

Attaching Viridian Longbow or Sword of Kaldra to a deathtouch creature is a fine tradition. As is giving a deathtoucher first strike or a first striker deathtouch. The two abilities combine to create an incredibly powerful effect, but that's okay because you need to draw two different cards, and pay the mana to combine them.

You'll note that Wizards have avoided creating any first strike deathtouch creatures lower than mythic rare for the past 15+ years. Glissa, the Traitor is the only card in Modern to have both abilities naturally. This is because having both abilities at once is incredibly powerful, and the same applies here. You're giving players all the parts of a combo at once, and letting them dominate the board with them.

I wouldn't be surprised if this became as annoyingly prevalent in Limited as Pack Rat. Being in two colours would help make that a little less regular, at least. It'd still be a windmill-slam first pick though.

If you really really wanted to put this in a set, I'd probably suggest moving it to (and remove the activation cost), and see whether Creative would like to make it a legend.

I think that changing the casting cost to could work. though a quick look at the Basilisk's that Wotc have made already the only red one is a one and all the others are straight up mono green. What about changing the cost to ?

Also not having the " cannnot be regenerated" clause is a big difference to the cards that have been cited in comparison to this card.

No, it really isn't... preventing regeneration is practically a corner case. It's irrelevant in 98% of the times Visara or Avatar is activated. It's utterly irrelevant to the main point of how board-dominating the effect is.

You're right, though, when proposing I did forget this was a Basilisk. I assumed you'd change the creature type.

I'd like to keep the creature type line if at all possible. Would there be a fair cost to the activated ability? Maybe just adding a cost to give it deathtouch until end of turn? Though a quick search shows that only one basilisk so far doesn't out right kill creatures it interacts with.

Having deathtouch on a basilisk is perfectly fine. The problem is the activation that lets it eliminate one opposing creature per turn with no risk to itself.

A few other possible solutions:

Deathtouch and ": ~ fights target creature" (monogreen)

Deathtouch and "Whenever ~ attacks, target creature blocks it if able" (monogreen)

Deathtouch and ", : ~ deals 1 damage to target creature with toughness X or less" (probably )

I guess asking for 3 colours could be enough restriction too... this ability on a monogreen Basilisk but costing maybe to activate, or this ability on a Basilisk costing to activate. At that point the player's had to jump through enough hoops that they deserve a powerful effect.

This is all just my opinion, of course. Feel free to see what others think.

They've already done a Basilisk that kills things with virtually no risk to itself... Sylvan Basilisk... I know that it doesn't work aggressively.

I can see adding a third color to the card at the activation point. I think I'll do that.

I thought that by now somebody would have said something about how this basilisk rubs salt in the wound by both killing one of your creatures and pinging you for a damage.

Nah, green already has trample.

That part is fine.

It is ": Destroy target creature" that's a lot less fine.

I won't say it can't be done, as a hugeass mythic. Still, three colours and a high activation... well, maybe. It makes it harder for this to be an annoying lockdown.

Nobody cares about the damage to the controller, just like nobody cares about the anti-regeneration clause, because they don't matter. The only point of life that matters is the last one. I can't count the number of games where I've been 1 life to 20 and gone on to win. Sylvan Basilisk is also fair because it doesn't dominate the board, it just gets in for 2 unblockable damage (it doesn't even work on defence). The thing to consider is, what kind of outs could the opponent have? A kill spell, obviously, but that's the "Dies to Doom Blade" argument which is discredited. The opponent only has so many kill spells to go round (And this actually doesn't die to Doom Blade, amusingly.) But imagine an opponent who casts a 5/5 flyer every turn. This creature can keep them at bay without breaking into a sweat.

I never thought of the Dies to Doom Blade or to kill spells in general. Though I did keep it's toughness low to allow nearly every burn spell ever to kill. It also dies to any instance of fights another creature. I did adjust the activation though. Now it needs three colors to use and with out red it's just a 3/2 deathtouch.

Is the card how it stands now balanced? Do the costs need to be adjusted?

Yeah, I think this is probably okay.

Cool, glad to have finally got a working version of the card done and polished.

The Idea of a Basilisk Assassin would not leave my mind.