On the less happy side, I found out that my reading comprehension is pretty horrible. While at the FLGS last night I learned that eSkarre's feat is much nastier than I thought (makes friendly models immune to attack or makes enemy models unable to attack instead of making models immune and unable at the same time), and followed that up with a double revelation about Slipstream. First the Slipstreamed model has to be placed completely within 2" (I'd been playing it as just within 2"), which is unfortunate but not earth-shaking. Then I found out that the Slipstreamed model isn't placed completely within 2" of where the Slipstreaming model finishes its movement, but instead completely within 2" of where the Slipstreamed model was when the Slipstreaming model passed it by, which actually did shake the earth. These two revelations combined mean that the extra movement gained from Slipstream goes from a potential 10" (2" behind a Seraph when it starts to 1.99999" in front of said Seraph when it's done moving) to a flat 2". This is quite the difference and means that a) I've been hosing EV pretty hard over the last couple of games, b) Legion is actually nowhere near as mobile as I thought, and c) a second/third Seraph moves somewhat down the list (though I still think it's an amazing beast.) In retrospect the way I was playing Slipstream was way overpowered, on par with (or better than) feats like Strakhov and pVlad, which is out of line with its low cost of a single Fury. In my defense, the wording on Slipstream is obtuse at best. Upon hearing I was doing it wrong, I reread it a couple times without seeing what it was I was missing before I finally caught the subtle nuances of the language. PP is generally good about making things clear, but this time not so much. The biggest disappointment has been you, Internet. You've been good about pointing out where I've done things wrong in the past, and while I haven't put up a ton of Legion battle reports (yet) there's enough of them up that someone should have caught it by now.
Shame, Internet, feel shame.
(Pay no attention to the fact that I should have figured out how Slipstream worked myself.)