When new mainline entries actually acknowledge characters and events from past side stories, even in a really small way, instead of just ignoring or retconning them
The Dead Space remake from 2023 adds new text logs name-dropping characters like Alissa Vincent from the 2008 animated movie Downfall, as well as Lexine Murdoch and Gabe Weller from the 2009 Wii spin-off Extraction (Lexine and Gabe also appeared in the 2011 Dead Space 2 DLC Severed, so they’ve been climbing the ladder for a while).
The Believer, a 2020 episode of The Mandalorian, has Migs Mayfeld confronting his former commanding officer over their shared role in Operation Cinder, an event which was first introduced in the 2015 Shattered Empire comic series and later covered by the campaign of Battlefront II in 2017.
Halo Infinite from 2021 features the Banished as the campaign’s main antagonists, after they were first introduced in the 2016 RTS spin-off game Halo Wars 2.
Idle dialogue from Sonic Frontiers in 2022 includes a mention of Sticks the Badger (from 2014’s non-canon Sonic Boom animated series) and Tangle the Lemur (from 2018’s canon IDW comic series). Tangle and her totally platonic friend Whisper (also from the IDW comics) also appear in Sonic Racing Crossworlds as of this week, though I wouldn’t quite count that as a mainline entry.
Edit: For some reason the last picture was replaced by a duplicate of the third one (it absolutely wasn't like that before I posted this) but it was just the cover art for Sonic Frontiers
The Believer, a 2020 episode of The Mandalorian, has Migs Mayfeld confronting his former commanding officer over their shared role in Operation Cinder, an event which was first introduced in the 2015 Shattered Empire comic series and later covered by the campaign of Battlefront II in 2017.
Halo Infinite from 2021 features the Banished as the campaign’s main antagonists, after they were first introduced in the 2016 RTS spin-off game Halo Wars 2.
Idle dialogue from Sonic Frontiers in 2022 includes a mention of Sticks the Badger (from 2014’s non-canon Sonic Boom animated series) and Tangle the Lemur (from 2018’s canon IDW comic series). Tangle and her totally platonic friend Whisper (also from the IDW comics) also appear in Sonic Racing Crossworlds as of this week, though I wouldn’t quite count that as a mainline entry.
Edit: For some reason the last picture was replaced by a duplicate of the third one (it absolutely wasn't like that before I posted this) but it was just the cover art for Sonic Frontiers
