Solution
R3b+
R3b+ threatens +R2a
R3b+
R3b+ threatens +R2a
N*2d
N*2d threatens G*1b
B2c+
B2c+ threatens G*3b
R5b+
R5b+ threatens G*3b
G3c
G3c threatens G*2b
L2c+
L2c+ threatens G*1b
B3a+
B3a+ threatens G*2b
R3b+
R3b+ threatens N*2c
B2c+
B2c+ threatens G*1b
R3a+
R3a+ threatens G*2b