SLKR lightspeed bundle items

Just looking at the SLKR lightspeed bundle at bit pricey at £35 but that's not the reason for this post. The bundle doesn't include the 5* Finalizer ship.  This ship is part of the requirement to actually start the event tiers. I looked along the 6 mission tiers and the Finalizer is never needed in any battle, they are all character battles. So why is the Finalizer even a required part of the requirements for the actual event? It's a pointless requirement as it's never needed or used and is just there to pad the farming for the GL.