We somehow left out how to join the motifs together. (Thanks, Severina!)
Asphyxiation Foundation Motif:
12: Repeat steps 1-11 with other three corners. [Fig 6]
To join on next motif (assuming you are not working them separetely and then sewing them together), work 2nd motif until you reach row 11 of first corner. Work until you reach 2nd picot of 2nd 10-chain loop. Chain 1 instead of chain 3, sc into picot of next motif (matching picots of both motifs), chain 1, sc 4. Connect next 2 picots of next 10-chain loop in the same manner. The second corner will be attached to opposite corner of finished motif the same way. Work a total of four motifs.