It would be the most extreme events in space. When spins are not aligned to each other,then the event horizons of the new black hole forms and so unstable that it could complex ripple in space and resulting gravitational waves are spreading.
A significant portion of the total mass (roughly 5% to 10%) is converted into gravitational wave energy.
If the spins are not perfectly aligned or if the masses are unequal, gravitational waves are emitted more strongly in one direction.
Image Source: Google