I would point out that the greatest Mossi kingdom was Wagadugu, centred on (you guessed it) the capital of Wogodogo - which, when it was captured and incorporated into the French colony of Haute-Volta, was renamed Ouagadougou. There's also precedent for going for a folk hero rather than a modern president - remember that AW's Berber mod has Tin-Hinan as its leader, and we're not terribly certain she existed at all. Yennenga's still very much relevant to modern Burkina Faso, in much the same way that St. George is to England, but I concede that that's not exactly enough. Also, Yennenga was a
stone-cold badass, and we need more of them, even if it is only so that Boudicca has someone to
lust after share war stories with.
(i ship boudiccaXcathy an u cant stop me)
I also wanted to go for someone that
wasn't a dictator, but, y'know, that's a bit tricky with Burkina Faso. I did have an idea for two UUs, one that upgrades into the other (like one of the ones in my Fiat Lux massive-Late-Antiquity-Britain-split-ideas pack), because according to Jane's the current army of Burkina Faso has a lot of emphasis on light, wheeled armoured vehicles - which could make for a very interesting Landship replacement, if not a completely period-accurate one. I'm not sure there
is a Landship replacement, modded or not... sod it, let's do it.
UU:
M8 Greyhound (replaces Landship)
Lower

Combat Strength than the Landship it replaces (40 vs. 50), but starts with a unique promotion, "Defense de la Revolution", which grants it double

Movement in Burkinabe territory; +1

Movement; Sentry I; and Medic I. Does not obsolete. Requires Oil.
This represents something about the modern Burkinabe army that isn't particularly well-known - its reliance on wheeled vehicles rather than conventional tanks. The unique promotion name is a reference to Sankara's Committees for the Defence of the Revolution, which were a kind of semi-military conscript force designed to "mobilise the masses". However, the role the Greyhound was meant for was a bit more passive in nature; it was a maneouvrable, lightly armoured vehicle designed to support armoured columns in WWII, which it did rather effectively. I like UUs that are less actively involved in killing stuff, and that's the reason they don't ever obsolete; they're designed to support the rest of your army in the lategame and still take advantage of the UA bonus.
Hopefully that's a bit more interesting. =]