Which faction needs a MASSIVE leap forward but also take a few steps back?

In recent times, GW has FINALLY progressed the story and setting of 40k for various factions but not without cost. The best example is the Fall of Cadia and Great Rift creating an undeniable massive victory for Chaos. However, that victory brought back Guiliman, Cawl, Primaris Marines, a semi-alliance with Eldar, the Indomitus Crusade, the Custodes and Sisters of Silence becoming more active, a stronger grasp of reason and logical and making Dante the Regent of Imperial Nilhus

Arks of Omen was another Chaos victory but the Lion is back with a cooler head, new abilities, and redeeming non-Chaos Fallen. Now he and Dante are collaborating to create strongholds on that side of the rift

During the Plague Wars, the Emperor became more psychically active and helped Guiliman. However, Khorne took a page from his book and spread the Murder-Curse through Angron.

We need more situations like that. Yes, this faction got a massive victory but the other faction still gained valuable something.

Let's look at Octarius. The Nids won but the Orks are mega-strong now, the Imperium are using Solblades to deal with them and Chaos got a few Daemon Princes.

There are rumors that Yarrick died thanks to Angron's frequent returns to realspace. Ghazghkull will want revenge for his old nemesis. Now we got Red and Green gods duking out to where Khorne and Gork & Mork take a front-row seat. If Ghazghkull wins then he'll achieve Krork levels of power. If Angron wins, Gork & Mork will likely intervene and Khorne will probably give Orks a tiny space in his realm. Another thing is how will Armageddon change after THE old man's death

Calgar dies or gets entombed in a dreadnought. The dreadnought is the likely option as there's no way GW is going to kill off one of their most established characters. Will Cato, Titus, and Uriel be promoted? How will Ultramar and the Ultramarines change under Agemman role? Same with Blackmane & Grimnar 

The Eldar needs SOMETHING! Thankfully, we have a new codex and models. Recently Jain has distanced herself from the Ynnari due to the requirement of Eldar lives. Then we have Vect instigating a Civil war. How's that going to play out? If Vect wins and then becomes a Dark Muse solidifying his control over Commorragh, how will the Haemonculi respond to being overthrown as the true leaders? What kind of damage can they do along with the other groups? If Vect loses, escaping to real space or to one of the sub-realms after the war. One of the most twisted individuals in the galaxy now has a stronghold in real space or can invite even more horrible things from the Webway in his new pocket dimension.