Typhus the traveller is host to the Destroyer Hive, having been worshipping Nurgle long before Mortarion. Indeed, in some ways, Mortarion's instruction to Typhus to cease using psychic powers was probably part of the reason Typhus first heard Great Nurgle's voice.
In the game, I've always struggled to comprehend how and where Typhus should fit in. In previous editions, I didn't use him outside Apocalypse due to his high points value. In 6th, he still has a very high points value, but has a couple of boons that weren't there before.
Firstly his destroyer hive has had a major boost. Once per game he can place a big pie plate over himself an hit everything (friend and foe) for S4, AP2. There's an obvious combination with Epidemius in here!
Secondly, there's the ability to morph chaos cultists in to plague zombies. Although there is presently some controversy about the unit size of plague zombies (personally, I think the wording allows big plague zombie squads), there is still a lot of scope. FNP, Fearless, and SnP means cheap objective holding. Hide them behind an Aegis defence line and there's suddenly a tough squad who'll hang around a while. The only pity is that they don't turn other combatants in to further plague zombies like Apocalypse does. One additional thought is whether Nurgle marked cultists might actually be better (particularly if we're going down the Epidemius allied route!).
Other than that, Typhus is a close combat exponent. He's a terminator with level 2 psyker abilities (all selected from Nurgle powers alone). The obvious thing to do then, is to join him with other terminators (Nurgle marked or otherwise) and deepstrike them on to the battlefield, or roll them up in a land raider. Typhus wants to make close combat where his S6 AP2 daemon-force weapon attacks will pay off gloriously. But then, he has the same issues as Abaddon: he doesn't really want to become a chaos spawn, and a daemon prince is probably only fractionally better / worse (depending on what statistics or abilities one considers). And his warlord trait (Lord of Terror) isn't going to be much use really.
So, what once was a character for Apocalypse or devoted Nurgle fans only, now has some interesting possibilities that will resonate in a number of army lists. Could a working plague zombie army be built using Typhus? Probably yes: hundreds of cheap troops, with some support and hard hitters spent on the spare points could work very well.