This would be my idea for a Marvel style first phases of Sentinel comics films.
Phase one - “freedom four”
Legacy - first film for sure, introduces the Parsons family and baron blade showing their history. Easter egg cameos aplenty, including Ryan Frost before the accident. Legacy defeats Blade but post credit scene shows Blade developing his anti Legacy serum.
Wraith - I think it’s too early to throw in a character as dark as Spite, but Ermine would make for a fun villain plenty of cat and mouse back and forth and playing on hidden identities. Also introduces Rook City and the crime there.
Tachyon - shows her being brilliant basically, and the moment of her gaining her powers. Villain would be Glamour. Easter eggs include an incomplete Absolute Zero suit.
Introduces Lillian Corvus and Krystal Lee, the latter in a mildly antagonistic role.
Post credits shows Lee stealing the friction suit.
Bunker - war film similar to the first captain America film, introduces the Ironclad project, GI Bunker and Grandpa Legacy Vs Fyodor Ramonat. Easter egg of Proletariat. Post credits shows modern day, Tyler Vance and injured Steven Graves returning from duty and Tyler being offered an opportunity…
Freedom Four - Baron Blade returns as the villain requiring all our currently known heroes to have to band together to take him down. Easter ego of cryo chamber.
Post credits scene reveals Ryan Frost himself and him refusing the absolute zero suit.
Phase 2 - “freedom five/vengeance”
Legacy 2 - more team based but with focus on Legacy and a more grown up Pauline as Young Legacy having to team up against Omnitron. Bunker shows up here for not having his own phase 2 film. Post credits scene shows Kim Howell working on the Omnitron remains and a blast of energy. A second post credits shows Baron Blade finding Proletariat.
Wraith 2 - introduces Parse and Spite. Wraith struggles with conscience over dealing with Spite. Parse, obviously, deals killing blow.
Post credits scene shows mysterious going on with cultists and Spite’s body and second post credits scene shows Baron Blade powering up Steven Graves (skipping a lot of his story, but eh… Films do that for some characters)
Nightmist - Lots of magic weirdness, cultists last seen in the Spite post credits scene. Lots of magic artifacts Easter eggs including the matriarch’s mask. Final villain is Gloomweaver but not directly faced as mush as sealed off for a while.
Post credits shows a young woman’s hand picking up an ornate mask and a fluttering of birds.
Tachyon 2 - features Ryan Frost chewing up all the scenery with snark from his cryo chamber. Cameo of Devra Caspit as new intern.
Villain originally appears to be Friction bitter over being replaced by Devra, but birds gradually appear more and more throughout the film and it soon becomes evident the real antagonist is the matriarch.
Post credits scene shows Friction a little worse for wear declaring she will have vengeance…
Freedom Five: Vengeance - big team up, Ryan Frost finally becomes Absolute Zero. Friction has minor role as team villain, lots of you again type jokes at her expense. Much less involved than the comic book story, fewer characters, much like civil war film compared to comic.
Phase 3
Expatriette - introduces the citizens of the sun and cameo of Dawn, but main villains would be some of the citizens themselves not Dawn. Pete Riske introduced.
Post credits shows the experiment to turn him into Setback.
Fixer - The Organisation as villains, main antagonist is the Operative with Pike as shadowy overseer. A lot of focus on the history between Fixer and the Operative.
Cameo from Wraith
Post credits shows Wraith and Fixer being taken down by an unknown entity.
Nightmist 2: Dark Watch - and that entity is, Spite! Returned from the dead by Gloomweaver and it’s up to Dark Watch to take him down. Also sees Lillian start training under Nightmist and Fixer as a brief secondary antagonist with cameo from Zhu Long.
Again, cameo from Wraith.
Legacy 3 - Baron Blade returns again with bombs! They really weren’t trying too hard with this one.
Freedom Five film - invasion from Citizen Dawn.
I expect the rest of phase three would be new characters getting films, likely the Prime Wardens characters finishing with an Argent Adept/Prime Wardens film where they team up against Akash Bhuta and a second Freedom Five film to keep familiar characters still in there, against Voss following the Tempest film.
Phase four - working up to Oblivaeon? The Legacy film for this phase would be Iron Legacy.