I won’t go into any gameplay or mechanics tweaks or techinical issues. Please take the same approach and leave out complaints about the game. Thank you.
-For the game’s lack of character and general story; Written lore could be added, Warhammer is a source of bottomless pit of lore, why not implement some scriptures or even books in the game both for newcomers and lore veterans, the Mourningstar could even have a library room or the loading screens could have some cool scriptures of lore. Another example is the book on the mourningstar where you can access the penances, instead it can have some cool stories or some background information changing weekly or monthly. This idea has endless possibilties which can be implemented in the game with relative ease and minimal resource.
-Codex: A codex section where you can look about the enemy types, monsters, their background and for example their weekpoints and everything about them would be a solid investment. It could include the operatives, cities and missions.
-Splash arts: Everytime you load into the mourningstar, you see the same spash art (you know which one I’m talking about). However Warhammer 40k has some of the coolest spash arts and concept designs. This can be multiplied with relative ease again.
-New global condition: Mega-horde. I don’t know about you but one of my favourite things in the game is reaping hordes with my hammer and chainsword like mad. How about a game condition where there will be same amount of elites but just multiply the hordes 5 even 10 times. I could hear you say yes already!
-Demonhosts: this has been brought up before, most of the time demonhosts are skipped because it’s a lot of risk and no reward situation. Some loot could be implemented or even a penance with a really cool skin or accessory ( kill 1000 demonhosts etc.) I’m still working on this. Penance would be too grindy I know.
Anyways, these are my takes as of now and I would be excited to read yours.
May the Emperor guide your hand.