Nice

The dual threats of Qxb3# and Rd4# mean that white needs a Checking spree that either ends in a miracle Mating net or a perpetual.

1 Qc6+ NxQ (If Ka5 then Qb5#)
2 Nb8+ NxN+ (if Ka5 then NxN and below ensues one move sooner)
3 cxNb8 (N)+! Ka5
4 Nb8-c6+ Ka6
5 Nxb4+ Ka5
6 Nc6+ Ka6
7 Nb8+ Ka5
8 b4#