So now the arrowverse is all but over I have to say I enjoyed it for the most part and honestly the only thing that disappointed me was the Legends of Tomorrow not getting a finale. I said on twitter that a crossover with Superman and Lois as finale writes itself so here is what I came up in a few days.

 Superman saves the Legends 

First scene is a normal morning on the Kent farm. Everyone getting ready for work and school. 

As everyone is heading to the car out of the sky skeets (booster gold tiny robot helper) crashes to the ground and plays audio of the Legends of Tomorrow just shouting 'Clark help'.

The next scene is a flashback of Booster and the Legends in a cell which is fully walled with a security door and they are arguing with each about who to call, Flash, Superman etc. In the confusion they mentioned Supergirl was on another earth which makes Booster confused and he sends Skeets to the Superman in S&L.

The opening animation plays except the S&L logo turns into a LoT logo.

We now have General Lane arriving at the Kent farm with a high tech laptop. Lane listens to the message and hears Sara Lance's voice a recognized it as he said previously 'I have seen heroes from other worlds' and the proceeds to show Superman a video on the laptop which shows footage of Sara Lance and the Legends from one of the old arrowverse crossovers. From the footage Clark decides he will help them as they must be heroes like him.

Skeets has now transported Superman to just outside the cell door where the Legends are and knocks on the door and asks for Sara. Sara is relieved that the message got across until of course she discovers he is from a different earth (a few jokes ensue). Clark says he will get you them out of there but when he tries to break open the door he can't. Behrod mentioned that crossing from different earths could make you just slightly weaker resulting in Clark being strong but not enough to break them out so Sara slips a lock pick under the door which of course she has handy.

Now Clark is trying to pick the lock but completely does not know what he is doing. The legends each have goes and guiding him how to do it but none them explain it to him properly until we get to Sara who guides Superman to unlock the door. 

Now all the Legends are in the hallway and then an alarm goes off and time agents start coming down the hall which results in the obligatory action scene where everyone kicks ass (except Gywn).

Everyone now makes it to the control room where they see the waverider being dismantled on the screens. 

Another fight scene through halls until they make it to the hanger and everyone makes into the waverider.

The team take off to get Superman back home and thank him for his help but then discover that the universe jumping plus the dismantling of the waverider means that they have one more trip which gets them back to the mainline arrowverse.

When they get back to their universe they crash land the waverider in the present day and evacuate as it explodes. Then legends then walk off into the sunset talking about what they will do now. 

Booster Gold of course mentions he thinks he will try to be a superhero since he has skeets who can knows everything that will happen and maybe he can do some good that way.

Ava and Sara say it is time for a new adventure of starting a family.

Gywn and Alun think they will continue to work on time travel experiments in the Welsh countryside and Gideon and Gary say they will help. (Gideon wants to help but Gary just wants to come so he can be with her). 

Zari and Behrod say they might go to Hall of Justice and see if they can be of any use there. (Joke about how the wonder twins are guards at the hall of justice in the comics and that sometimes Zari and Behrod have been referred to as the Wonder Twins.)

Astra says she is going to go Master her powers and takeover from Constatine. Spooner says she will help Astra as she just wants to shoot demons in the face. 

The last thing we see is the Legends walking off into the sunset.

The end.

What does everyone think? Personally I would be satisfied if this is how it ended for Legends of Tomorrow. I just did a brief outline but I'm sure a professional TV writer (preferably one from the LoY writers room) could improve on this emensely.

Also if possible the Superman role could easily be taken up by Nate (Steel) from Legends instead and they could just do this as their finale separate from Superman and Lois but realistically if we do get a Legends of Tomorrow finale then I do think it will be as an episode of another show and I think Superman and Lois is the most likely candidate at this point in time.