Since this has been speculated and I am not really an expert on the Phoenix Force as you X-Men fans would be.
I have read the Dark Phoenix Saga, Phoenix; end song and Avengers v X-Men which featured the five phoenix hosts.
Thanos is dying and needs a cure, he has always had a goal of acquiring ultimate power.
As the Phoenix force is a cosmic entity as Thanos' former love Death is, could Thanos become infactuated by it ?.
Is the Phoenix force more female orientated ?, could it appear as Jean Grey to seduce Thanos ?.
I am confused if the Phoenix Force is a force of life or a harbinger of death.
Would Thanos' nature as a character corrupt the Phoenix force into becoming the Dark Phoenix or Dark Phoenix-Thanos ?.
Any expert opinions would be greatly appreciated from this X-family of fans.