  We derive the limiting form of graviton radiation in gravitational scattering
at transplanckian energies ($E\gg M_P$) and small deflection angles. We show
that --- owing to the graviton's spin 2 --- such limiting form unifies the
soft- and Regge- regimes of emission, by covering a broad angular range, from
forward fragmentation to deeply central region. The single-exchange emission
amplitudes have a nice expression in terms of the transformation phases of
helicity amplitudes under rotations. As a result, the multiple-exchange
emission amplitudes can be resummed via an impact parameter $b$-space
factorization theorem that takes into account all coherence effects. We then
see the emergence of an energy spectrum of the emitted radiation which, being
tuned on $\hbar/R \sim M_P^2/E \ll M_P$, is reminiscent of Hawking's radiation.
Such a spectrum is much softer than the one na\"ively expected for increasing
input energies and neatly solves a potential energy crisis. Furthermore, by
including rescattering corrections in the (quantum) factorization formula, we
are able to recover the classical limit and to find the corresponding quantum
corrections. Perspectives for the extrapolation of such limiting radiation
towards the classical collapse regime (where $b$ is of the order of the
gravitational radius $R$) are also discussed.
