From Marvel Age Annual #2:
Phoenix 6-issue limited series
Writer: Chris Claremont
Artists: Rick Leonardi/Dan Green.
“It is basically Phoenix discovering who she is, what she is and why she is and discovering her origin,” Chris Claremont said. “It is a much more psychologically oriented series than most.” The Limited Series begins with the results of what happens in X-Men #209. Power Pack and Franklin Richards are among the guest-stars. And the featured villain will be Spiral.
This limited series was also announced on the letter pages of the Uncanny X-Men #208, 213, and 215. It was to occur between the Uncanny X-Men #209 (when Rachel leaves with Spiral) and the Excalibur Special (where Rachel escapes from the Mojoverse and ends up in London). In the Uncanny X-Men #209, Phoenix was mortally wounded by Wolverine and then lured into the Body Shoppe by Spiral, the former assassin of Mojo.
From the letter page of the Uncanny X-Men #208:
As you have no doubt seen from this issue, Rachel's going to need all the friendship and support and affection she can get, not simply in the X-MEN but also in the upcoming PHOENIX Limited Series we have planned for later this year, which Chris Claremont will be writing and Rick Leonardi penciling. We think it'll be something as different and special as the lady herself.
And then from the letter page in the Uncanny X-Men #213, it was apparently delayed until late 1987. And lastely, the Phoenix Limited Series was promoted in the Uncanny X-Men #215 letter page:
We have a PHOENIX Limited Series in the works, written and inked by the X-MEN team supreme of Chris Claremont and Dan Green, and penciled by the aforementioned Rick Leonardi! This series should answer all your questions about Rachel and them some!
Another blurb from Marvel Age #43 (Oct. 1986):
Coming Soon: PHOENIX Limited Series
She's from a future that may or may not be ours. She's living in a past that isn't quite the way she remembers it. She's Rachel Summers, daughter of Scott Summers and Jean Grey, Cyclops and Marvel Girl of X-FACTOR! But her mother was Phoenix, and in the Marvel Universe Scott and Jean aren't married. In fact, Scott has a son by his wife Madelyne! These are definitely not the average problems that face most young women. But then, Rachel isn't exactly average.
This is the background for THE PHOENIX Limited Series, written by Chris Claremont and drawn by Rick Leonardi and Dan Green. Rachel having retreated to current time to escape from a grim anti-mutant future, has joined the X-Men and is using her telepathic powers as the new Phoenix. But since she adopted her mother's name in the battle against the Beyonder, nothing has gone right.
The plot of the Limited Series deals with the dread villainess Spiral (remember her from LONGSHOT and, more recently, the Freedom Force?) and lots of psychological ramifications and complications. It examines how Rachel is coping with being in a past that resembles - but isn't quite - the one that proceeded her world. She will meet Power Pack in the first issue and see little Franklin Richards. In her time, Rachel is in love with a grown Franklin! Here he is a child, and she is much older than him, and this situation will cause her to do some serious soul searching.
There will also be lots of cameos and guest appearances, lots of flash-forwards, and lots of fantastic visuals by Leonardi and Green. We'll have more information on the Limited Series as its publication approaches, so stay tuned.
In an installment of Cup of Joe, Quesada had editor, Andy Schmidt contact Rick Leonardi about the project:
The series was going to be written by Chris Claremont and inked by Dan Green. Rick said it dealt with Rachel and her relationship with Franklin Richards and the Power Pack. The going logic at the time was that it got too complicated with past/present/future continuity and was subsequently shelved with I believe less than an issue having been penciled. That’s the whole story, folks, wish I had better news to report but it seems that this project was no where near completion before it was killed.
Chris Claremont wrote the script for at least the first few issues. Rick Leonardi penciled the first issue and a few pages were inked and lettered.
This Phoenix Limited Series is not the same as X-Men: True Friends miniseries published in 1999 featuring Phoenix and Shadowcat.