I could try and start a discussion.
Let us look at teamkilling strategies.
>Ways to murder
>NCorp Yi Sang
>Fell Bullet Yi Sang
>Thorcalgia Ryoshu
They reward you with either big damage (Bullets) or with strong poise generation (Thoracalgia)

>People who benefit from deaths
>BLMeursault
gains InMemoriam which gives him swordplay of the homeland every turn while upgrading his poise generation.
>Kurokumo Heath and Ish
gain Battle Ready, which is 1 slash power up and 30% more slash damage while increasing their bleed potency and count application, and for Heath specifically, it gives him a permanent reuse to his counter coin. This is extra good for him since it means he has access to his s3 every turn as long as you get 3 lust resonance.
>Sancho
gains more hardblood per dead bloodfiend and when all 3 are dead she gains Responsibility which gives +1 clash power and makes her deal and take 20% more damage.

>Benefits on death
>LCE Yi Sang and Faust
both give resources on death and Yi Sang applies rupture potency and count.
>Snek Gregor
constantly gives poise to whoever replaces him.
>Tarnished dragons
both Sinclair and Hong Lu unleash nukes once they die

>Interacts with death
WildHunt Heath is the only who does it iirc as he can revive someone whose health drops to 0 and keep them alive for one more turn which does mean that you can have someone die twice for the above EGOs that need kills.