In this note we continue our study of unidirectional solutions to hydrodynamic Euler alignment systems with strongly singular communication kernels φ(x) := |x| −(n+α) for α ∈ (0, 2). Here, we consider the critical case α = 1 and establish a couple of global existence results of smooth solutions, together with a full description of their long time dynamics. The first one is obtained via Schauder-type estimates under a null initial entropy condition and the other is a small data result. In fact, using Duhamel's approach we get that any solution is almost Lipschitz-continuous in space. We extend the notion of weak solution for α ∈ [1, 2) and prove the existence of global Leray-Hopf solutions. Furthermore, we give an anisotropic Onsager-type criteria for the validity of the natural energy law for weak solutions of the system. Finally, we provide a series of quantitative estimates that show how far the density of the limiting flock is from a uniform distribution depending solely on the size of the initial entropy.This system represents a multi-dimensional hydrodynamic version of the celebrated Cucker-Smale flocking model introduced in [7, 8], with a huge number of applications ranging from biology or robotics to social sciences, see [4,29,21] for recent surveys and references therein. The system (1) is designed to describe the interaction between agents governed by laws of self-organization with communication protocol encoded into the kernel φ.In many realistic situations and applications, the communication among agents takes place in local neighborhoods induced by short-range kernels. Particularly interesting is the case of singular communication kernels. Clearly, singularity at the origin strongly emphasizes local communication.For models with singular kernels given by φ(x) := |x| −(n+α) for 0 < α < 2 the operator L φ ≡ L α becomes the (negative of) classical fractional Laplacian:R n f (y) − f (x) |x − y| n+α dy Λ α := (−∆) α/2 , 0 < α < 2.