Same as Fig. 3 but for BH-166 and its host galaxy. We can notice the presence of other BHs (black dots) that are going to merge soon with the main one (associated with the spin vector). ① At high redshift, the proto-galaxy has again a disturbed morphology. The accretion of gas onto the BH is rather chaotic. ② Here also, once the galactic disk is formed, the three spins are well aligned. ③ Although the main BH experience several mergers and its host galaxy one minor merger, the galactic disk is stable with all spin remaining aligned.