Well, one of the losses was when Kiora would not have saved me.
Having said that, Kiora literally won me match 3, and then again in match 4. I didn't realize just how busted the card was, I thought it was something similar to Elspeth Conquers Death from Standard, which had a weak 2nd mode, but Kiora is on another level entirely. All three of Kiora's effects are worth at least a card, in fact they're probably worth more than a card.
Sleep for example is a strong card in aggressive decks, while
In Bolas's Clutches is a veritable bomb.
After going 3-1 I punted match 5. Game 1 I had no chance, since I drew only 2 lands in my top 12 cards. Game 2 I sided out Elspeth's Nightmare because opponent had Mogi's Favor, which can kill Caryatid and therefore take me off black mana, but somehow boarded in Viper on the vague theory that opponent had green creatures so it'd be good (this is also a X/1 creature??). Then I proceeded to punt by throwing away a 6/6 Beetle. Opponent was on 5 life and the board was Typhon + 6/6 Beetle + Arachnir vs. his 2/3, 2x 2/2s, and 0/1 (from Discordant Piper), plus he had the rare +4/+4 mantle aura in hand having just returned it the previous turn. I attacked. Of course he took the trade and I lived to regret it. Should've just waited while the Beetle grew, forcing him to play Final Death - which as it turned out he didn't have.
Didn't help that I could've suicided my Typhon later to make it 7/7 and block his Underworld Charger, but I didn't, and decided to escape my Chimaera instead to trade. Opponent had a bigger graveyard than me, which meant of course I couldn't bring back my Chimaera the next turn while he could bring back his Charger, and sacrificing the Typhon was no longer an alternative. I wound up using One with the Stars on the Charger, which meant opponent's 10/6 boar the next turn forced its way through the board stall and won the game. Sheesh. After winning two matches on the back of Kiora, I ought to have realized that I could be patient because Kiora will eventually win me the game, I just have to draw it. But then, if I play badly and lose, I can't complain. In hindsight I should probably have brought in turtle, which neutralizes the Charger.
Arachnir was once again mediocre. I'm really not seeing it I'm afraid. The escape cost is not cheap, and as a 1-mana card, it's not killing anything relevant (off the top of my head the only common X/1 flyer is the black harpy, which is already filler). There aren't that many flyers either. It's possible it's a good card - it sure [i]sounds[/] good on paper - but it's repeatedly failing to impress me. The rare +4/+4 aura however impressed whenever it was played against me.
On to next draft, I guess.