Brigid, Hero of Kinsbaile
With any one of the multitudes of cards that give deathtouch, exile on damage, or lifegain, this card becomes amazing. Even without those cards, this card can easily deal with the multitude of token decks out there as well as make opponents rethink how they're going to block because, with that 2 extra damage, they could easily lose their field. Essentially, this card can easily become a boardwipe on a stick.
Chainer, Dementia Master
A friend of mine made this deck and I first thought that the life payment in its ability wouldn't make this card a good general. I was wrong. Yes, it can get expensive in the late game, but with a properly built deck full of boardwipes and life leeching, this card can make for a very, very scary general.
Chisei, Heart of Oceans
Now, you may think to yourself that having to remove a counter from a permanent you control every turn is a bad thing and it's understandable why you'd think so. However, Reality Twist, Dark Depths, and Mystic Remora would all like to disagree, along with a few other cards that like having little to no counters on them. This card can prove to be a formidable lockdown general, especially against monocoloured decks.
Circu, Dimir Lobotomist
This card is definitely more suited towards one-on-one battles, but it can really shine there. You may think to yourself that 1 or 2 cards per spell isn't really a big thing, but it can really be effective. Over the course of 10 turns, by only casting 1 spell a turn, you can remove around 15% of your opponent's deck from the game (assuming some were multicoloured spells). And how many tutors put the cards they looked for on top of their owner's library? How about Sensei's Diving Top? This card can easily get rid of that pesky little thing.
Homura, Human Ascendant
Suicide general anyone? Yeah, it may be a 6-costing 4/4, but it turns everything you control into a dragon when it dies. EVERYTHING INTO A DRAGON! I don't think I need to explain this card anymore. It turns everything you control into a dragon.
Nath of the Gilt-Leaf
This is Edric, Spymaster of Trest's evil twin. Forcing your opponents to discard every turn is pretty good, but forcing them to do it at random is infinitely better. The fact that is also gets you a benefit is pretty nice as well. Black/green elf decks can be very scary and this card is a very scary card to lead your army with.
Sachi, Daughter of Seshiro
Anyone who knows me in real life knew this one was coming. This card's second ability is just amazing. Look up mono-green shamans. You'll be surprised how many really, really good ones there are. That fact that when this card hits the table you've probably doubled your mana base is just awesome. This is also fun with Snake Basket because of the buff it gives.