Stripped EGR bolt of death.... Out of ideas on how to remove

Hey,

I have a 2014 Gen 3 Prius and I'm in the mist of replacing the head gasket. I've removed the all of the bolts of the egr except one. The one that is in the front. I have the tool to remove the bolt, but when I went to remove, I didn't loosen the nut and the head of that bolt tore. I then removed the nut, tried several tools to get the bolt to release, ended up stripping it. I can't remove the egr due me being unable to remove this bolt. I had to disconnect the inverter cables (and I took a pic before hand when I go to re-attach them) for some more room to operate. At my wits end here.

I've tried a damaged bolt/stud tool. Think that did more harm than good. Tried to re-thread with my tap and die set, but I think the bolt is hardened and I would need a hardened kit to re-thread. I don't have a welder so I can't tac weld anything to remove the bolt. Literally at peak frustration with this thing and I'm running out of ideas... hence this thread.

Any other suggestion on how to get this thing removed? Maybe call a specialist? Is there a tool I can get that can give me enough grip to twist this off? With it being stripped, the tools I currently have don't provide enough grip and there isn't a lot of space to insert a anything large in there.

Also, I have been trying to find this very part but the online manuals I look at, the part number is different and the sites are unable to confirm if it will fit or not. Any help with identifying the right part would also be great.

Thanks in advance for any ideas I can try.