Your mother was a hamster and your father smelt of elderberries!
An impenetrable human wall, solid like a rock, strong like an ox with steel plate armor thicker than a dragon’s hide. The king’s guard is there to serve one single purpose – to protect his king and his army. Even though he carries a big blade, his massive amount of armor impedes flexibility, speed and attack power. To compensate for this he has a really sharp tongue and throws a lot of insults around, enough to attract attention from the most battle hardened enemy.
Previously, there was no single-purpose tanking unit available in Castle Raid. If you wanted to protect one of your weaker units your only choice was to deploy a footman or perhaps a knight. The problem being that neither of them are pure protection units. Thus you would always find your knights out sprinting your archers or your footmen not being tough enough to absorb the font-line damage. This makes the king’s guard the number one choice for protection, at a reasonable cost.