qgd6+ maybe
FFA Puzzle #7 (The first actual puzzle)

Don't you need to say how many moves it takes to win the game?
It is quite involved but it is forced. No need to say how many moves as when you find the full line you'll know.

Qa6-g6+
(1.. Be2-h5+ .. Kb11-c11 )
(1.. Qg3-j3+ .. Qc9-c10 .. k10-k9
2. Qj3-h5 .. Qc10xQh5 .. k9-k8
3. Be2xQh5+ .. Rb10-c10 .. k8-k7=D
4. Qa6xe10 .. Kb11-c11 .. Qk7-k1
5. Qe10xRc10+# ) .. Kb11-a11 .. k10-k9
2. Qg6-b11+
????????????
Not quite I'm afraid

Wow, very puzzling. Maybe you can also make an easier one sometime so you can remember your own lines? KEKW
Red to move and win.
[StartFen4 "R-0,0,0,1-0,0,0,0-0,0,0,0-57,37,43,13-0-x,x,x,8,x,x,x/x,x,x,6,yP,1,x,x,x/x,x,x,bP,4,yP,yK,1,x,x,x/1,bK,7,yN,4/1,bR,2,bP,5,yP,1,dgP,1/2,bD,9,dgP,dgB/11,dgP,2/14/rD,13/6,rP,7/3,rP,8,dgK,1/x,x,x,rN,rP,1,rD,4,x,x,x/x,x,x,rK,rB,rP,5,x,x,x/x,x,x,8,x,x,x"]
[Variant "FFA"]
[RuleVariants "DeadKingWalking EnPassant PromoteTo=D SemiAnonymous"]
[CurrentMove "0"]
[TimeControl "2 | 10"]
Hint: Blue has just played e10??