After discovering the history of Voltron and Prince Lotor’s plans the team bands together in the hopes of creating a coalition to take them down but not everyone is focused, causing tension amongst the Paladins.
The New-Old Black Lion
Despite Voltron wanting to get as many allies as they can in the fight against Lotor, Keith isn’t playing the same game as everyone else. He’s so focused on finding Lotor that Voltron becomes a second thought. While Voltron puts on a show to get people riled up Keith is sneaking into Galra ships with the Blade of Marmora. It also goes back to him wanting Shiro to pilot the black lion again.

Flickering Myth
Keith isn’t in this season much. I can only assume that’s because Stephen Yeun may have been busy. He’s most present in the first and last episodes, but if Keith is your favorite character it may be disappointing.
Waking Up
At the same time, Zarkon is waking up and is not happy with Lotor and his plans. Even his team waivers as the stress of being hunted questions their loyalty to Lotor. Lotor takes drastic measures to keep his father off his tail breaking his squad apart forever.

Nerdist
Meanwhile Haggar is having an identity crisis. As we know she started to remember her past and it continues through this season, but not at that point where she might return to who she used to be. The progression is starting though.
Join the Coalition
Old plot-lines are solved while the fight continues. Voltron takes their “show” on the road, impressing other civilizations, and convincing them to join the fight. Like many times during the show it seems as if Voltron will turn the tides in the war but a few twists here and there and it ends with a cliffhanger.
The season is only six episodes long, which is disappointing and it goes by quick. No time for filler just focusing on the plot while having a bit of humor here and there. I would put this up there as being more of a “darker” season with more deaths and more at stake as characters get closer.

Kotaku.com
Overall
I just wanted to put this out there: one of the episodes displayed on Netflix shows a spoiler thanks to the screen-shot. The name may give it away as well, but just something to look out for since the episode keeps you on your toes but knowing the ending doesn’t help.
I’m never disappointed with Voltron. It’s fun but also gritty with high stakes, especially for a show considered to be for “kids.” But it’s only six episodes with more to talk about leaving it for next season. And I assume there will be a next since it ends on a cliffhanger. In the mean time we’ll continue to theorize Shiro being a clone. And that idea isn’t answered or even put into light.

Den of Geek
Until next season.