
any absolute yaoi masterpieces that don’t involve raping mc?

Depends on what your definition of masterpiece is and what you like. If it's art, plot, originality and transcends time, one's greatest work (this one may not work because mostly alive) ... I haven't read anything I found original but: Reunion,
Why Are You So Kind To Everyone Except Me?, Kiss me if you can, Semantic error, BL Motel, Love Shuttle, I found were decent, art beauty is in the eye of beholder so ╮( ̄▽ ̄)╭

Okay no particular order. All really cute and heartwarming with no super manly ukes. I will say nekoxneko is a switch couple so it's either gonna be a hit or miss. No historical or omegaverse unfortunately since I can't think of any that are yaoi and don't have sexual assault. Now I could recommend some shounen ai historical, just none with the sexy time lol.
https://www.mangago.zone/read-manga/honto_yajuu/
https://www.mangago.zone/read-manga/motoyan_papa_to_hitsuji_sensei/
https://www.mangago.zone/read-manga/neko_x_neko/
https://www.mangago.zone/read-manga/wolf_me_up/
https://www.mangago.zone/read-manga/cherry_blossoms_after_winter/
https://www.mangago.zone/read-manga/cupid_ni_rakurai/
https://www.mangago.zone/read-manga/dear_signal/

I didn't see your response. I think my answer still stands, but let me fix it.
Manly assertive uke : Boss Bitch Baby, Pizza delivery man and gold palace, Kiss me if you can <- omegaverse, novel has no rape, I assume the manhwa shall not have any, uke is badass and wholesome!
Omegaverse: Omega complex, love shuttle, Pendulum: Kemonobito Omegaverse, Heat and run (first couple story)
Historical: The rogue prince is secretly an omega, Bad friend, Dawn of the dragon (1 unconscious pushy kiss session at the start, but it's really a sweet love story with a puppy seme and an assertive uke)
Greenest flag of them all: many would consider the seme in Reunion as the one.
Happy reading!

best bls you’ve ever read

these two -
Song of Reverberation
https://www.mangago.zone/read-manga/song_of_reverberation/
The Promise
https://www.mangago.zone/read-manga/the_promise/
also this list -
https://www.mangago.zone/home/mangalist/2758080/

legit everything on this list , and everything i stated at the top ( yes i like toxic bls too )- and twisted ones
https://www.mangago.zone/home/mangalist/2898367/

underrated and not well known bls with power bottoms

Yess!!
Read these two in this specific order, tho not a sequel they're kinda connected, also don't be put off by the art at the start, it changes for the better in just a few chapters :
Song of Reverberation
https://www.mangago.zone/read-manga/song_of_reverberation/
The Promise
https://www.mangago.zone/read-manga/the_promise/
also this list has many power bottoms:
https://www.mangago.zone/home/mangalist/2758080/

any bls that seme is lowkey psychotic but turns into a puppy (or kinda) when it comes to uke, or just straight up yandere

my sugar father bam bam site: https://booktoki463.com/novel/1707750?stx=%EC%BD%94%EB%93%9C%EB%84%A4%EC%9E%84+%EC%95%84%EB%82%98

The Spooky Love Tale of Gongchan Seol
https://www.mangago.zone/read-manga/tales_of_seol_gongchan/
Makitakun No Koiji wo Jamasuru To Shinu
https://www.mangago.zone/read-manga/makitakun_no_koiji_wo_jamasuru_to_shinu/
A Link Between Relationships
https://www.mangago.zone/read-manga/a_link_between_relationships/

u describe this one so well...want a literal definiton of yandere? yep, you've got murderer llwellyn
https://www.mangago.zone/read-manga/murderer_llewellyn_s_enchanting_dinner_invitation/
any actual non irritating twinks? meaning no crybabies
RAINBOW CITY ヽ(`Д´)ノ (SA in chap 3, best to skip)
Little mushroom
Into the thrill
The foul
Till and Luka from Alien Stage but it's an animated series so...
https://www.mangago.zone/read-manga/sangyang_the_wanderer/
Please, I think of you to read this Pookie
I actually have it saved! but i can’t tell if it’s depressing or not
I wouldn’t say depressing but dramatic and angst romance.
is it completed ?
No but season two is about to end
To explain it a bit better it it’s not really depressing but it has a deep storyline. it’s more about adventure, self-discovery, and some really stunning storytelling. The art is amazing, and the world-building pulls you in right away. Plus, the action and character development is chefs, kiss and make it so worth the read and past the angst. If you’re into stories with depth but not just endless gloom, this one’s definitely for you pookie (≧∀≦)