Nin is underperforming. She's a cool wincon, but hard to make work for three reasons:

1. There isn't a ton of X synergy without the green add-on to the cube (Glinteye Avernus Cube: https://cubecobra.com/cube/list/3e15b7f0-2462-4183-9007-ee3a037f8f52)
2. I've removed most of the mill cards because they're hard to balance in a way I feel is satisfying
3. I personally had a bad experience with Ertai bounce control and I don't know if Nin can compete well with the increase of triggered/activated ability counters.
4. She don't got haste. She can come out turn one pretty easy and make it to upkeep, but reasons 1-3 push her over the edge.

All that said, Ghyrson acts as a good signpost and gives Izzet an option to compete with Rakdos burn.

No one is taking Arcane Infusion so I figured no harm in a swap. Third path also has cross synergy with brudiclad, cyberdrive and pingers