Which version of TWRP did you install? The latest should be 2.6.3.0 and everything should be fixed and working in it.
Here's the direct download link:
Techerrata Downloads - Downloading openrecovery-twrp-2.6.3.0-endeavoru.img
You're nearly there! Flashing a ROM is done in recovery and on the phone, you need to do a little bit in fastboot again, but it's not much.
We'll go for Venom unless there's anything else you want? Have a look at the screenshots and feature list in the venom thread and see if it's what you're after:
[ROM] [DISCONTINUED] Team Venom ViperX 4.0.6 - | HTC One X > XDA
The download link is here:
xda-developers - View Single Post - [ROM] [DISCONTINUED] Team Venom ViperX 4.0.6 - Sense 5 JellyBean | orig. OTA | Tweaks (ViperX 4.0.6). It will be a zip file about 600MB in size.
Once downloaded, open (don't extract) and look for a file called boot.img. Copy that file to the fastboot folder you flashing recovery from.
Once done, connect your phone to the PC and copy the zip file over to the root of your SD Card/phone storage.
Disconnect the phone, then reboot back in to TWRP. Head to the Backup menu and take what's called a nandroid backup (this is basically a snapshot of your phone in it's current state so you can restore it if something goes wrong with the flash), it should take about 10 minutes.
Head back to the main menu, then select install zip from SD Card and double check to see if the zip file you copied over is visible, but don't flash it yet, just check to see it's there.
Once done, head to main menu in twrp again and look for the wipe section, perform a factory reset and wipe the cache and dalvik caches(instructions will be on screen).
Head back to the main menu, install zip from sd card, select the zip file, confirm and let it do what it needs to. The aroma installer should be relatively self explanatory. If it asks if you want to do a full wipe, say yes. If it asks about a kernel, you're using the stock kernel, and you don't want to/haven't flash a custom one.
Once finished, go back to the main menu in twrp, select reboot, then bootloader. Head to fastboot and then connect your phone to your PC again, open a command prompt, navigate to the fastboot folder (or wherever the boot.img file and fastboot.exe is) and type:
Code:
fastboot flash boot boot.img
Let it flash, then type:
Once done, disconnect, reboot and you should boot in to Venom. First boot might take 10 minutes or so.