The ultimate is good, but not if your opponent has ways to get a ton of life
It's typically pretty difficult for red to remove permanents besides artifacts and creatures, so anything that offers a widers pool of potential targets is rad
Depending on your deck, you might also want to look at Clever Concealment, Flawless Maneuver and Cosmic Intervention the latter of which is a lot of fun with fetchlands and mass land destruction, or board wipes when you run a lot of strong EtB effects
I dont want to get sidetracked there, especially when Mark Rosewater has made it abundantly clear that the topic is not open for discussion at this time
Then she drops the cost of everything by 1 generic mana, not just artifacts and enchantments which you might expect since she's an Artificer, but everything
Unfortunately, you cant give your lieutenant a Battlefield Promotion and run it as your commander