Beings of Tash Kalar
As with most leaders, the pattern represents the captain in front of an infantry line formation.
It allows you to command your other pieces to move and fight.
It offers less moves than the Cavalry Captain, but it is more versatile. It can be strong also with common pieces (as both moves are combat) and it better arranges patterns for the following beings (because you may move two pieces). However, its pattern is less compact and thus harder to create.
Originally, the combat moves had to be performed with two different pieces. It was more thematic, but weaker. This is why now it is possible to move one piece twice.