I think this is a very underrated card. A lot of people have talked about how the ability makes this work with Klinklang, but I actually think it goes best in good old beatdown as a lategame sweeper. I play a 3-3 line with a couple of Mewtwo and Landorus each. Mewtwo and Landorus can put on the early game pressure (Virbank Lasers also help). If they survive that onslaught and take out your EX, they'll be dealing with Lucario hitting for 120+. Even if you don't get the early game pressure and they get ahead in the prize lead, Lucario can come in and OHKO EXes (and is especially good against Darkrai),
Of all the quirky decks I've built online, this one seems to be the most effective.
Of all the quirky decks I've built online, this one seems to be the most effective.