So here is one Tabiya of 5...Nc6 & 8...Bc5!? with 9...0-0 in the Halloween Gambit:
White has several options here :
* 10. Ne4 Re8 11. Bd3 Qxf6 12.Qe2 Qd8 is interesting
* 10. Na4 Re8+ 11. Be2 d6 12. Nxc5 (12. f5) 12... dxc5)
* 10. fxg7 Re8+ 11. Be2 d6 seems bad for white
* 10. Qh5 is playable
There is also 9...Qxf6 that is interesting:
So maybe this 8...Bc5 variation is not strong enough to be called solely the best variation versus the Halloween Gambit.
I actually guess now that this line is the most annoying for white:
1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Nxe5 Nxe5 5. d4 Nc6 6. d5 Ne5 7. f4 Ng6 8. e5
White has to take the knight on f6 and here black 9...Qxf6 seems best.
PANFR: 10.Na4 Re8+ is good as it allows ...Bg4 in some lines. Moreover is there is no Bishop in c5 later(Na4 played), then Kf2 is possible instead of the pinned Be2.