Do a full wipe, flash Endy. If you are still on a bootloop, you unlocked your device on htcdev.com, you must manually flash boot.img with fastboot.
- Full wipe if not coming from Endymion V3.0/V3.1/V3.2
- Install V3.1_base
- Optionally flash V3.1 addons package
- Install V3.4 Updater - do not flash addons package after this, the order is important!
- You're done
- BUT the first thing you should do after setting up your phone is go to "settings->tweaks->rosie options->enable quick scroll " and choose semi 2D/3D. Trust me on this.
Again, do a little reading before jumping into stuff...