Nightmare of the 3.0r

Hey yall, I'm new and in desperate need of help or even ideas.

Vehicle is an '05 Legacy Outback with the demon 3.0r, which I'm convinced is the black cat of motors. Last year, the head gasket ripped on the exhaust side- so it held pressure, but blew antifreeze out the reservoir cap. To limp it thru, I made the dumb mistake of tossing some Blue Devil sealer in and it sealed every crevice in the motor. Took it to a family friend who's a mechanic, he ordered a new motor. Same issue, holding pressure, blowing antifreeze. We figured maybe it was a blocked heatercore. Took it elsewhere to find block checker added to the antifreeze came out yellow, so another head gasket. Mechanic refused to replace it, so my husband and I personally purchased a new used motor with 54k. Note to add, old motor fired up and ran, new motor has ZERO spark.

Car gets fuel just fine, cranks and turns over just fine, will NOT fire. Initially attempted the spare in case it was the immobilizer, no go. Today I put in a new crank shaft sensor, no go. Removed the sparkplug boot and a plug, tested for spark, and it's dead. This car has been sitting for over a year, and we've dumped nearly 5k into it between labor and old motor, and now the new motor. The mechanic were currently using is dragging his feet on it.

Any tips on what may kill spark but not fuel? Our next move is taking it to a specialist and having the other garage's work checked over in the event they clamped some wires or fried the computer/wiring harness, but this is my last ditch before another possible 3k garage bill. I'm at wits end with this beast.