E-way Bill where 3 parties are involved

Who should Generate an eWay Bill? Registered Person – Eway bill must be generated when there is a movement of goods of more than Rs 50,000 in value to or from a registered person. A Registered person or the transporter may choose to generate and carry eway bill even if the value of goods is less than Rs 50,000.

The person causing movement of Goods (i.e. Supplier) is required to generate E-way Bill.

Party A can create eway bill in bill to ship to mode.

Party C can generate eway bill in bill from ship from mode.

Party B can generate e way bill in combination of bill to ship to and bill from ship from mode.

Yes, I know about law. But the question is whether both party need to create Eway bill or any one of them create.
If any one of them can create then what should other seller do when GST department ask for eway bill in goods sold over 50k. 
And if both need to create then how we can update transporter details in both Eway.

For one transport only one e-way bill is required. E-way bill can be created by anyone of seller, buyer or transporter. Preference should always be that seller to make e-way bill.

Yes Transporter is only 1 who is picking goods from Party A and delivering to Party C. Now assume only Party A will make Eway bill from Bihar to Hyderabad. 
Then what would Party B will do because he is also a seller selling goods to Party C and buying from Party A, what would he keep for his record. 

Party B need not issue e-way bill

In that case if GST office asks them to provide Eway bill because sale was over 50000 then which document they will provide them because it is mandatory for them to create Eway bill for goods supplied. 
 

The invoice from Party A will denote it is bill to ship to and so will his e-way bill. That will be the proof for party B

Thank You CA Altamush Zafar for the clarification. 

B sells goods to C and purchases from A and tells A to send directly to C . 

here. A makes invoice of B of 40 units of 100000 rs per pc totaly 4000000 and ships to C 

B makes invoice of C 40 units of 110000 rs per pc total 4400000

my question is if A makes eway bill he will enter all bill details like date , bill no. qty and rate. but here B is actually selling the goods. so how will B and C show if tax officers ask for document.