I don't like it. For a 2-energy retreat cost you're going to lose 2 energy one way or another each time you KO a Pokemon (unless you're playing doubles, in which case I'm just not going to comment). Add to that how it'll KO most basics and even some higher-evolved Pokes (I can't think of many legal non-EX/stars right now that run much above 100 or so), and you're losing 2 energy virtually each time you attack. I guess that's what the power is for, but the fact that it ends your turn means you can't do anything for an attack, period.
On the other hand, I guess not ending your turn would result in a nearly-infinite OHKO engine...
6/10