Thace:

Thace was genuinely one of my favourite side characters in the show (both so far and the first time I saw it). As a character he really gives insight into Marmora's ideals and operations— the complete dedication to his mission and the skill to evade both the druids' and Haggar's suspicions of him long enough to help Voltron set up their plan. Willing to die for a free universe, or to bring it any bit closer to freedom.

I'd have loved to get a comic or something exploring his background a little bit, maybe about how he got to the position he did (since he seems to have been Marmora's highest ranked infiltrator).

Slav:

Slav's a fun way to drop in establishing information and foreshadowing, especially because it's absolutely hilarious every time he shows up on screen. You might forget that he is genuinely hyper-aware of how the universe (and the greater multiverse) works, right up until you hit a line like "now there's no reality in which we all make it out alive!" during the attack on Zarkon's command and it punches you in the face.

Shiro:

I'm going to miss OG Shiro for the rest of time. It's no wonder things become disjointed when he disappears/dies, he was exactly the sort of leader that the paladins needed to pull them together. He cared for them, he cared for the cause, and he had the dedication and skill to back those things up. He was just good. His and Keith's dynamic has always been my favourite.

Keith:

I talk about Keith a lot. That's because I think about Keith a lot. In the early seasons it's so blatant that he has the potential to become an incredible leader for the paladins, but he's just not ready. He's got these issues and insecurities that he has to work through before he can put himself at the head of Voltron (literally and figuratively), but then Shiro's gone and he's the only one Black will accept, and that's that.

The groundwork of a leader is laid in him, but when he's grieving and desperate to find Shiro again, it's...possibly not the best time to see how well that holds up. Actually, it's more like turning the ground under the foundations to quicksand and seeing how well they hold up.

This was all possibly not helped by him having only just found out that he's galra, having had to deal with the change in dynamics with the team (Allura's hatred and that entire time he spent with Hunk getting the scultrite), and just generally not being in a very stable part of his life. Sure, though, we're going to put the guy who both suggested and then immediately volunteered for a suicide mission in charge. Not that they had much of a choice, but lord. Cut the poor kid some slack, he's like...eighteen? nineteen? All things considered, he's holding out pretty well.

And the final comment: the noise I made at "Summon Prince Lotor" may be the cause of my recent sore throat. (Only joking. Mostly)