An Adepta Sororitas Exorcist is an ornate missile tank armed with a highly effective Exorcist Launcher. It has decent range and hits especially hard against enemy armoured vehicles. It has the Faithful rule, which can be used to make it Fearless and gain an Invulnerable Save.
Penitent Engines are incredibly destructive units that charge headlong into battle, galvanised by the need to expunge the guilt their pilots feel for sins they have committed. Armed with Heavy Flamers and Power Saws, their targets cannot take advantage of cover or even armour.