Ville c2 bricked? unable to mount SD card, no recovery

Hi guys, so a while ago I flashed Venom Rom to my one s c2.
In the recent weeks I noticed, that the memory was getting more and more full. But I couldn't find the files responsible for that.
So I did a factory reset, which didn't help. So I tried to wipe the storage in TWRP 2.6.3.0. . Furthermore I did a "total wipe" so I checked every option in the wipe section.
After that, I couldn't boot the phone, because there seemed to be no OS installed. So i tried to flash the ROM which I loaded onto the phones storage but it was gone.
When I tried to transfer a ROM to the phone's storage it said "unable to mount sdcard". So I couldn't transfer any files to my phone.
After hours of reading through various threads, I tried to get it back to stock by running a RUU.
Unfortunately I couldnt find the exact one for my device. This is what fastboot displays when i type in "fastboot getvar all":

version: 0.5
version-bootloader: 3.01.0000
version-baseband: 16.15.20.29_M
version-cpld: None
version-microp: None
version-main:
version-misc: PVT SHIP S-ON
serialno: SH25YW404475
imei: 352762055439276
meid:
product: villec2
platform: HBOOT-8260
modelid: PJ4020000
cidnum: HTC__102
battery-status: good
battery-voltage: 4014mV
partition-layout: Generic
security: on
build-mode: SHIP
boot-mode: FASTBOOT
commitno-bootloader: 9006d003
hbootpreupdate: 11
gencheckpt: 0

So I tried these ones (tried running as administrator as well):
RUU_VILLEC2_U_ICS_40_HTC_Europe_1.09.401.101_Radio _16.11.20.02U_16.05.20.11_M2_release_261381_signed
and
RUU_VILLEC2_U_ICS_40_HTC_Europe_1.11.401.101_Radio _16.12.20.02U_16.05.20.16_M2_release_261661_signed


But they didnt work out. It always displays "error 155" and on the phone's display it says "older hboot version" .
And now I can't even access the recovery anymore... And because I tried to run a RUU I relocked my bootloader....
I really can't find a RUU with the correct Radio and don't know how to identify the hboot version of the RUU.
I already tried to flash a recovery again via fastboot, but it didn't work as well :

C:\*****\platform-tools>fastboot flash recovery twrpvillec2.img
sending 'recovery' (6420 KB)...
OKAY [ 1.291s]
writing 'recovery'...
(bootloader) signature checking...
FAILED (remote: signature verify fail)
finished. total time: 2.079s

I'm really lost guys, I hope I didn't hardbrick my phone.
If anyone has any suggestions, please help.

Thanks!