Sorry to hear that. There's probably some internal damage inside the silicon structrure so there's very little you can do about that. I do have an idea to try though.
Power up your RPi and then connect RUN (using P6 pin) to 3V3 via a 100 ohm resistor. Then measure the voltage on the pin. The point is to see if the voltage will raise from the ~0.4V or not. The way I see it, the whole SoC might be fried or just the RUN input. If the latter then maybe you could still somehow "overpower" it to register as high, enabling your Pi to start. At this point there's not harm in trying.
If the voltatge doesn't rise above some 2V then could even try connecting RUN directly to 3V3. Worst case scenario you'll see some smoke
Keep in mind that R15/C97 are likely a part of some power-on reset circuit so without it the Pi might not be very stable at start. Try a few times.
By the way, did you test D18 diode after desoldering it? Did it fail in any way? Also, did the SD card survive (those too are 3V3 only)?