LT is superior to Phoenix Force
Multiple universes and multiple multiverses which house these universes, in every universe there is a version of each being, abstract and entity, which has been shown in certain comics that each universe has its own abstracts; shown in the Korvac what if. Except for a few, Living Tribunal, TOAA, the phoenix force, now if Living Tribunal is above all universes, multiverses, alternate realities, what if universes, and existences, then that would mean their is only one Living Tribunal but omni like. If this is so then that means the Living Tribunal showed in all comics including what if's is canon showing of Living Tribunal since he is above all of these universes and multiverses and their is only one of him meaning the one Living Tribunal showing must be the Living Tribunal. This brings me to my next point
From: "What If the X-Men lost Inferno"
Living Tribunal is shown to be holding the Phoenix as a mere object or a Child's toy, now if Phoenix is above reality constraints then that means that their is only one phoenix not multiple phoenix's, not one for each universe. If this is true that the Phoenix force is Omni like then then that means that there is only one phoenix force just as their is only one Living Tribunal. The Living Tribunal is shown to be able to wield it and hold it like a mere object. Now if their are multiple phoenix's, one for each respected reality and universe, then that means the Phoenix force is not omni like. If you claim that it is only a what if and thus is not canon, then you should know that LT is above all Marvel multiverses including What if's meaning his showings are canon since their is only one LT and that is him. Now if Phoenix is weaker in a what if, then that means she is not Omni like, for if the phoenix force was purely Omni then it would be unlimited and unrestrained no matter what dimension or universe it is in, but clearly it is not here.
The Phoenix force is not the most powerful force in existence, nor do I believe that it is second. If the Living Tribunal is above the Phoenix Force, then that means those above the Living Tribunal are above the Phoenix Force, thus Korvac of the alternate dimension which out powered the Living Tribunal is arguably more powerful then the Phoenix Force, the HOTU which defeated the Living Tribunal is more powerful then the Phoenix Force, the IG which the Living Tribunal was not sure if it could defeat him or not, thus would be more powerful then the phoenix Force.
So many feats brought up in favor of the Phoenix Force, yet the Phoenix force never did anything to save the multiverse when it was threatened by the HOTU or the IG, one could argue it was purely because the Phoenix Force saw it as nothing but child's play, but I believe that to be untrue. The Living Tribunal steped up to defend the Marvel Multiverses, but did the phoenix force, no it did not. Thanos even made it to TOAA and stalemated him. The Phoenix force was helpless to do anything against Thanos and the HOTU. If it took TOAA to undo what Thanos did, and in doing so TOAA burning out his powers, then thinking that the Phoenix Force is more powerful then such I find to be untrue.
Claiming that the Phoenix force is this fundamental force of creation and thus is master of all created, but know this that creation only extends to what you take part in creating, the phoenix may be a force of creation, but when you take it to a level of thinking forces become thoughts and emotions of some one much more powerful and beyond the imagination and thought of the one created.
Point being, the Phoenix force is not the most powerful force in Marvel, nor do I believe it to be the second, or the third, or the fourth.