After 12 volts battery replaced, I heard the ABS accumulator, then nothing. Dead. What next?

The old 12 volts battery gave issues before bellying up, in fact, I had to leave it overnight in another city because it didn't jump start at all. Disconnected everything from the 12 volts and ran other errands, then came back connected and it jump started this time off my wife's Prius. Arrived home with the hope it was a discharged battery, but no, once I tuned it off, it didn't start again. Tried jump starting it the next day to take it Toyota, nada, and at this point it went into a weird state where if I connected a jump starting battery, the yellow turn lights would come on steady, but nothing more. Then removed the 12 volts battery to test it and it didn't hold charge, and barely gave 8 volts. Bought the new one, put it in, and just like I said above for the title, heard the ABS accumulator do it's thing, and then nothing. No lights ever in the cluster, no cabin lights, no response from remote, no blinking key in the dash. Nothing. And the new battery is good, during the entire process I bought a charger which diagnosed the old as bad, and fully charged the new up to trickle charge. Voltage comes out good off the new one. One more weird thing, I tried jump starting the car with the new battery installed and helping with the jump starting battery I have, and it showed as a short. Jumper cables even got hot. right after the spark the ABS accumulator made the same noise it made before with connecting the new battery, and then back to zilch, nada, niente, nothing.
Ideas? Will I need a computer to diagnose what's going on? Is there something else I can try before paying tow to Toyota and paying through the nose? Car is still fairly solid at 240K miles.

 

Battery is the super expensive Toyota sells as replacement, yet not the original Japanese, I believe it's Sure Start or True Start or something like that. Terminals are clean, and properly connected. I found a couple of blown fuses and replace them. Now I have head lights, cabin lights, the ABS accumulator still makes the sound AND pushes back on the brake pedal. No turning lights yet, and the Bluetooth key is being recognized.
The power button lights up green for the first push (not ready, just on for radio and similar but radio and other than the warning lights are still gone), and then it lights up orange when trying to go into "ready".