OK, so your getting the SDDM not loading issue that has been reported in both the Manjaro, and Arch forums the last few days.
There is more than one way to fix this.
1: First thing to try is just rebuilding your initramfs in case it didn’t get rebuilt against systemd 235 during the upgrade proccess. If that still fails, try adding your GPU Kernel driver [i915 +/- intel_agp (suppresses the ACPI error messages, must be before the i915 entry), radeon, amdgpu, nouveau] to the MODULES= line of your mkinitcpio.conf file for early loading, and then rebuild the initramfs.
2: Try the 4.4 LTS kernel (has far less issues) if your hardware support is there. Alternatively you could also try one of the newer kernels. There have been mixed results reported from just changing the kernel however.
3: Try downgrading SDDM to 0.15 and add it to your pacman.conf ignore list temporarily untill this is fixed upstream.
If any other solution to this particular issue are presented I’ll report those as well.