Okay, I'm, going to impart upon thee the most deadly and dreaded of the SPAs tactics...
The Desolation Engine Choo-Choo Pain Train!
How's this work? Get 4 or more SPAs. Out-activate your opponent, if you can.
Get Levi to cast Blessings of Desolation on the back-most SPA. Get Rusty Alyce to cast Burn Out on another, or the same SPA (Depends on if you can keep it alive easily, you don't want the cast-upon SPA to get nuked.).
Move the SPA swarm downfield in a diamond formation- Keep Pace lets you push each SPA in base-to-base back into base-to-base, so you can drag around 5-6 SPAs as a group.
Once you get to your second-to-last SPA, move it, then cast Concentrated Deformation. Place the new DE as far upfield as you can. With 4 SPAS, you can get around 15 inches upfield, including the DE base size.
Since the last SPA never activated, the new DE has 2 APs, and since it's a replacement effect, is still affected by both Blessings of Desolation, giving it a auto-Warping Touch, and Burn Out, giving it a Reactivate.
Charge the DE downfield. Overall, you get somewhere around a 20 inch threat range. Not too shabby. Finish t charge, and get te free melee attack from Melee Expert, cast Desolation for (0), end first activation.
Reactivate the DE, and either swing 3 times against what's in your reach, or charge again. After this, or before, depending, cast Desolation again.
Your goal here is to kill at least 2 enemy models with te DE's melee attacks, giving you two new SPAs. Then, if your DE is killed, you're good to make another DE next round if your first is killed.
All in all, the DE is a Glass Cannon, but what a cannon!
Have any questions? I'm not the greatest explainer, so if you need clarification, please ask.
-Chris.