Advisor manipulated/threatened me into sharing my first authorship My last Phd work was submitted to a high impact journal (IF &gt;35). The manuscript came back for revision with 2 positive comments and 1 no-suggestion on my last day in his lab. Given its positive comments, I expected to go for next round of review as long as the comments are fully addressed. The comments requested simulations and experiments, which I supposedly would not be able to perform as I graduated and was leaving the next day. So my advisor threatened me on my last day to submit to IF (~5) journal or share my first authorship to someone (person X) who was not involved in the project at all. For the later, he reasoned that X needs to commit full-time ~ 4 months just for revision and stop all other works. Although I explained to go through comments first and discuss and that I can revise, he did not agree any of it. He asked me to choose 1 of his options, no negotiation (like giving co-first after X shows to put significant effort). I agreed to give X co-first authorship under the condition that major revisions will be done to address all reviewers' requests and convince them. Then my advisor privately told X will be the co-first and to revise none, minor, or major; choice is up to X. They spent 1.5 months only for quick revision, without addressing all comments. I told X about the problems with the revision, but no any reply. It was rejected directly by the editor. (At this point, they already broke the deal.)
Then they submitted to another journal, got rejected by the editor again.
Another journal (IF &gt;10) finally passed the editor and came back for revisions. All 3 reviewers are positive. Yet the editor asked for all the comments/experiments to be fully addressed. My advisor did not even notify me about this decision. X told me that they wanted to submit to IF ~5 journal because too many experiments need to be done for the revision. X said need ~ a month or more to revise, and my advisor wants X to focus on looking for a job. So X asked if I am okay with this decision to submit to IF ~5 journal. (This is how I know there is a revision requested.) I am very mad because how X can deserve a co-first if they did not even put in effort and time! The revision comments are very positive, but they said they think it will not go through. (I am basically #w$%t&amp;f?)
Similar things happened repeatedly during my PhD in his lab. I am very mad, but I am helpless. I used to hope this work would help my faculty job search if it gets published. This time, I did not want to &quot;waste&quot; this work while it originally even had the chance to go through IF&gt;35 journal, but they messed it up since then.
Note: My advisor is a complete a**o who used to call/write bad recommendation letters for those who were against him.
Any suggestions on how to handle this?
UPDATE 1: So they agreed to submit a revision. Knowing that they will not treat it seriously like last time again, I revised the majority myself, incorporating old experimental data. There are still many simple experiments (~ 2 weeks worth of time) needed to be done. How can I make sure they will do the job and do it right?
These are your options:

Focus on your new project in a new lab working with better colleagues.
Do the revisions yourself.
Let the former advisor do whatever they want.


I agreed to give X co-first authorship under the condition that major revisions will be done to address all ...

You agreed to the co-first authorship.  You should not break that agreement.  Unfortunately, revisions being &quot;done&quot; is subjective so you cannot punish the other party for breaking their part of the agreement.  Next time, only agree to someone's authorship after they have earned it.