If you gain an amount of life "for each" of something or "equal to the number" of something, that life is gained as one event and the ability of Knight of Dawn's Light applies only once
Plus it has a built-in way to gain indestructible, which is always nice in a commander
I searched engineer into Gatherer and found these nifty workers: [c]Goblin Engineer[/c] [c]Thopter Engineer[/c] From here, its just a matter of searching through a bunch of cards and finding anything that fits our theme
At first glance, the Library of Alexandria Carfolite showed me is close to perfect
The first is To Infinity..., which states that when you play this character, if chosen opponent has more cards in their hand than you, draw cards until you have the same number
It has likely won more games per deck inclusion than any card on this list too