Hello! Before talking about the deck itself, you shall know that the antient bonds expansions has a lot of good cards for arcanyst, and old arcanyst is a little slow control archetype. I think, it can be hard to reach diamond with the old arcanyst deck verions. Also arcanyst is not easy to play and you will need to practice.
That said, if you still want to play arcanyst i've made 2 list for it. Kaleos verions is a little harder to play. Both list are theorycraft, but are based on the old decks i've played before the bloodborn expansion.
Owl Beast is your only best wincon, do not ever throw it first. Always bait for removals on lantern fox, dioltas or four winds magi.
You mostly skip turn one as player one, unless you have a chakri and you are sure it won't die.
Heal yourself and try to get late game.
Juxtaposition is a tricky spell, can help you a lot. Use it wisely.
Onyx Bear Seal is a must have hard removal for big treats.
Killing edge works great with pretty everyting you have, if it survives.
Lightbender can be helpfull in the current meta.
The scientist is, probably, the reason why you play Kaleos over Reva, unless you do not like Reva at all.
Spiral techinque can work great as a finisher.
Reva have more ways to remove minions and that's pretty much it. But since you want to play in late game, it might be better. Also her bbs is better.
Ancient Bonds arcanyst decks are much faster and, in my opinion, you shall work for those cards, if you want to play arcnyst. But if you want to reach diamond using songhai, probably will be much better to just use a control reva deck or a midrange kaleos.