Bashin\' your enemies\' heads in, basically
He comes in 2 varieties, with a Captain/Master profile respectively. He does cost 25 pts. more than a commander (basic costs), but he also comes equipped with a power weapon and a 4+ invulnerable save. Give him a pistol, a crux terminatus (and maybe artificer armour), and you have a deadly close combat machine with 6 attacks when charging. Not exactly packing a heavy punch (that\'s what terminators or other people with power fists are for), but able to put down an average of 3-4 enemy troopers per cc phase. But that\'s not even the sweetest part:
Captains or Masters will allow you to use their Ld value anywhere on the table. Nice. But the Chaplain will make himself and his Command unit fearless (no need to test

)
and able to reroll failed \"to hits\" if they charged in the same round.
Now, imagine the abowe Chaplain with a 9-10-man squad, all carrying ccweapons and pistols, charging into an enemy squad... 36
repeatable attacks - at least!
Like I said: Chaplain = Enemy trooper basher. Plain and simple.
Unless, of course, you wanted to know about fluff... then it\'s a slightly different story...