Here is my last deck and i'm pretty excited to share it.
First of all "Lord of waste" isn't a 7/3 any more but a 6/4, and this is better. of course, in this deck everytime you'll summon him you'll gain 3 faeria by sacrificing an "Annoying gnat".
That's exactly what you're also gonna do with "Oath of oblivion", "Death Walker", "Demon wrangler" and "Doomgate, door to oblivion": you sacrifice a gnat, lose 2 HP and the gnat return in a random location. If the gnat reappears close to the enemy orb that's fine, let's play "Oath to oblivion" or "Demon wrangler" (and say thank u).
Of course you can do the same thing by sacrificing a "Cartographer" and gain an "Explorer" card, which will be very good to trace a path right to the enemy orb, and gain 2 faerias on the same occasion.
And u can sacrifice a "Wind soldier" after having attacked the enemy orb too.
You just need 2 yellow lands to play all the cards , the rest will be drawing, uncolored lands or another yellow land close to the enemy orb for your "Wind soldiers".
You'll lose a lot of HP, and u can be sure that your opponent will often kill your "Annoying gnat" just to make u lose 2 HP. That's why i decided to play 3 "Healing song", 3 "Soul drain", and the excellent "Radiance, imperial airship", which goes very well with "Doomgate, door to oblivion" because you're gonna draw a lot of cards with it, and also because you don't need to play many lands (less lands=more draws).
"Doomgate, door to oblivion": this card is really good within that deck, you'll draw 1 more card/turn for 2 HP (as well as winning an "explore card" if u sacrifice a "cartographer" this way,in addition to the card drawn) and once the structure reaches 13 HP it is destroyed and you get "Ostregoth", a 13/13 flying with haste and charge 13 (!) who'll keep all the wells empty until he leaves the board.
What u must absolutly do when u play "Doomgate" is to sacrifice a gnat/cartographer/another creature immediatly after having played it, and if possible each turn after. If u don't do that the structure's HP will remain at 3 for one turn and this is too dangerous, especially if your opponent plays red and/or "Emperor's command".
With 5 HP he'll need 2 cards to remove it, and this is very good (=> card advantage, we've played 1 card he uses 2 to remove it)
Finally you don't need to play several "annoying gnats" together, if there are 3 copies of it in the deck it's only to have more chance to draw it, since it is the essential card of the deck.
Mulligan: of course you"ll want to draw "Annoying gnat" (or "Cartographer") at any price, but every cards are not bad to draw in your opening hand, except for "radiance, imperial airship" (too soon), "Healing song" (same) and "Oath to oblivion" or "Death Walker" if u don't have in hand an "Annoying gnat".
Test this deck and tell me what u think of it.
Have fun (and respect your opponent)!