I was thinking about ways to use Lieutenants as less-important or simpler supervillains. In general, it's super-easy to use them this way, even making up descriptions of powers to narrate a simple Attack or Hinder or whatever.
But even given the durability of Lieutenants, they can still go down pretty fast (especially if heroes team up on them, which is common).
What do you think of the idea of using 2 Lieutenants as one opponent? Each "Lieutenant" represents a level or tier of the villain. The character takes 2 actions just like 2 opponents. When one "Lieutenant" is defeated, the character remains on scene, though now only taking one action.
You could gve an ability to the Lieutenant (as the rules recommend) and then give another ability that only activates when the 1st level is defeated. This could even be a stronger ability because it's not available right away.
Using this, you could create simpler, easier to use villains who are not as durable as a formal supervillain, but who can last longer than regular Lieutenants.
Lieutenants are actually pretty durable, especially at d12. They can go down quickly if the heroes get lucky, but they can also sponge up a whole lot of damage if they get lucky or the heroes don't strategize well.
I wasn't thinking d12; I think that guy can stand on his own. I was thinking 2 d10 or maybe even 2 d8. And when the 1st "stage" goes down, he would reset at d10 or d8. In other words, I wasn't thinking "d12 w/2 actions, then 1 action at d6." My version is quite a bit more dangerous.
Perhaps set it up as a single lieutenant with say, one or two abilities on it's own. Add a challenge to the scene that, as long as it lasts, is powering up the lieutenant and granting it an extra ability (taking two actions on it's turn for example). The heroes could certainly fell the lieutenant without completing the challenge, or they could take down the lieutenant after removing it's powerup.
Either way, you've got a slightly more dangerous foe, and an interesting base to build the scene around.
Thanks for the comments. Adding a challenge to the Lieutenant is not nearly as powerful as making 1 guy the equivalent of 2 Lieutenants. The extra action was not the big point. The added durability was.
Adding durability to a lieutenant feels counterproductive.
Your sample d10 Leiutenant will take a minimum of 3~4 hits to take normally. Having them reset to a d10 post defeat once pushes that up to anywhere from 6~8 attacks at minimum.
For contrast, a d12 Leiutenant will take a minimum of 4~5 hits to take down normally, only one fewer than the reviving d10. You can then throw on something like +2 or +3 to Leiutenant damage saves, and get something that will likely take far longer to fell than the reviving d10 Lieutenant with a minimum of modification.
Another idea I'd have for hardiness would be a regen or recover ability they have. During their turn or as an environment twist they upgrade one die size and only to a max of their original die size.