May I ask why not Agony Warp? It seems to be a perfectly control sign, kills a dude and prevents 3 damage.
It's the type of card I think a new player would under-rate. I remember thinking most hard kill-spells were not very good when I was new, even though having them would have prevented me from losing a lot of games.
Now, part of teaching newbies is showing them that removal is an important part of the game. Depending on what the rest of the cube ends up looking like,
Agony Warp could be a viable option and is something I should be considering. Really the biggest strike against
Agony Warp is that it isn't necessarily interesting compared to some of the other gold cards I want to use. If you've a player has been playing magic for only a month, and they're given the choice between having
Agony Warp or a
Cunning Breezedancer, I think there is a significantly higher chance that they will pick the dragon over the spell.
However, now that I'm putting it on paper, my lack of reasons to run
Agony Warp other than "it isn't cool enough" and "it could be under-rated" probably doesn't justify not running it. There are definitely possible upsides to having a more efficient and less wordy spell in the format, even if it isn't "awesome" on paper.