D&D 5E There is already a Warlord in 5E.

[Illithidbix]

Page. 220 of the Volo's Guide to Monsters.

Warlords are legendary battlefield commanders whose names are spoken with awe.
After a string of decisive victories, a warlord could easily take on the role of monarch or general and attract followers willing to die for his or her banner.

CR 12 NPC with legendary actions, including:

The warlord targets one ally it can see within 30 feet of it. If the target can see and hear the warlord, the target can make one weapon attack as a reaction and gains advantage on the attack roll.

and

The warlord targets one enemy it can see within 30 feet of it. If the target can see and hear it, the target must succeed on a DC 16 Wisdom saving throw or be frightened until the end of warlord's next turn.

And the Survivor, level 18 Champion ability, or there about.

#Helping.
*gets coat*

 

[Sacrosanct]

Monster mechanics are completely different than PC mechanics, largely because monsters' abilities are meant to only be used for one encounter--the one in which they are IN the encounter. Not 6-8 of them a day.

 

[77IM]

Still, I think this is a good jumping-off point for a "Story First" approach to building a warlord (as opposed to a "mechanics first" or a "re-create 4E first" approach that many warlock diehards seem to espouse).

 

[Tony Vargas]

Funny, but not worth another thread. Might be worth a discussion in the Character Builds forum, though. "How can you approximate a Warlord in 5e?"