Assault Terminator Conversion

I managed to polish up a few terminators over the last few days.  I used forgeworld black templar shields and wanted them to have something a little different to a thunder hammer, so one of my friends suggested that I could make a "Thunder Lance" - having the same rules as a thunder hammer.  The result is below, a very easy conversion, but I hope it looks fairly effective.

An assault cannon term for my regular footstompers