If you’re playing the Historic Arena Open this weekend, I strongly recommend playing Grixis Phoenix or Golgari Food if you want to play the best deck.
Whether you like Best-of-One or Best-of-Three, both decks should be excellent in both formats. I’m not too experienced in Historic Best-of-One myself because it’s not a competitive format, but given how wide open the Historic metagame is, I can’t really imagine that it’s too different from Best-of-Three. I personally prefer playing Best-of-One on Day 1 because the games go by much faster and you have a couple losses to give.
If you like playing an off-meta deck, I noticed that GW Enchantress posted pretty decent records in the last couple tournaments in the past weeks.
Historic GW Enchantress by Satoshi Nakayama
Historic GW Enchantress by Vinnie Silverman
These two deck lists performed well in the last two bigger Historic events and could be decent choices for the Best-of-One field on Day 1, which is usually more filled with creature decks, especially if more people are on the same “fast games” plan.
The Nine Lives + Solemnity combo is great against creature decks and, for example, Izzet Phoenix doesn’t really have a lot of cards in the 75 that can break through it. On the other hand, it’s not particularly effective against sacrifice decks with The Meathook Massacre.
I wouldn’t expect to take this deck all the way to seven wins on Day 2, but if you like playing different decks, then I think it could be a fine choice, especially for the Best-of-One metagame on Day 1.