An Ultramarines Desolation Marine sergeant armed with a Vengor Launcher and its under-slung, belt-fed Castellan Launcher, as well as a signum targeting device that allows him to guide his entire squad's missiles towards their targets.
A Castellan Launcher is a long-range, anti-infantry weapon employed by the Primaris Space Marines of a Desolation Squad of the Adeptus Astartes that is of particular use against enemies in cover.
Desolation Marines all pack a little something extra under the barrel of their rocket launchers. The belt-fed Castellan Launcher can saturate the sky with guided bomblets that rain down on the enemy wherever they hide, catching them in a blast radius that extends beyond the wielder's line of sight.
It is the perfect weapon for flushing out cowardly targets -- and it fires separately from a Desolation Marine's main rockets, allowing them to pick and choose their targets.