The text on the scrollwork is Latin cooked up by Google Translate from the following:
IN THE NAME OF THE GOD EMPEROR AND THE HOLY OMNISSIAH, LET THIS MIGHTY
ENGINE OF WAR BRING FORTH ITS WRATH UPON THE ENEMIES OF MANKIND. LET ITS
LEFT HAND BRING FORTH FURIOUS HEAT TO CLEANSE THE GALAXY OF THE UNCLEAN
AND THE ALIEN. LET ITS RIGHT HAND SMASH THE TRAITOR AND THE HERETIC. LET
IT RAIN DOWN DESTRUCTION FROM THE QUIVER UPON ITS BACK. LET NONE STAND
BEFORE IT. IN THE NAME OF THE GOD EMPEROR AND THE HOLY OMNISSIAH!
which apparently translates to:
IN NOMINE SANCTAE DEI ET PRINCEPS OMNISSIAH DIMITTE IRAM SUPER TANTO
MACHINA HUMANITATIS INIMICOS FERAT. PURIFICATIONEM EIUS GALAXIA CALUERE
ACCONGERO SINISTRA POLLUTUM ET ALIENUM. FRANGIT DEXTRIS EIUS TRADITOR ET
HAERETICUS. DE EXCIDIO PHARETRA STILLABIT SUPER SE SIT. NEMO RESISTERE
EI. IN NOMINE DOMINI DEI AD CAESAREM OMNISSIAH ET SANCTA