Sukuna knows how he views love because he thinks love is trivial (愛など下らん). He is, in a sense, a philanthropic misanthrope as his joy revolves around humans and lesser beings existing. He goes back and forth a lot, but settles on humans being great. Without humans, he could not exist.

慈愛 is also commonly associated with parental love. So he is explaining to Kashimo like he is a child, and to Sukuna, they are all children because of how long he has lived.

これが 慈愛でなくて何だというのだ [If this is not affection/love, what is it?]

It goes back to the idea of love is both a noun and a verb. An idea and an action.

He further establishes himself as the number one by using another form of love: 慈愛 (じあい) - jiai. It combines both "mercy" and "love" together. He is really showcasing that he is able to showcase mercy by killing.

どう 他者と 関わり慈しむのかと問うたが [You asked how to relate to others and to love.]

What does it mean to love someone weaker than oneself? Sukuna answers that by killing those who admire them is giving them that love - he is performing that action of love.

This form of love is usually reserved for the BIG moments of your life. Think weddings or births.

The 2nd form of love he uses is 慈(いつく)しむ. This one is very fitting for someone who is God-like since the kanji means "mercy." This one means to love (someone weaker than oneself).

Subject omission in the original poem is important because a subject is absent until the last line where "you" is being addressed. I wish there was a better way of translating the poem without having to add "I" in order to express the intent of the poem.

Form and intention is especially important when it comes to translations because the English language is limited when it comes to different levels of addressing a subject when we rely on tone to indicate sarcasm or honor. The subject omission in the original language is important and essential.

媟 is the kanji that means "lust after, act indecently, lewd" so it begs the question of why didn't Kubo use a word that actually means lust? Why settle for a heavy word like "to want/to desire" especially with a kanji meaning of "longing, greed, passion, desire, craving?"

The origin of おまえ is that a long time ago, it was used for people of respect like nobles or even deities.

I have so many thoughts about the formation of this poem. The subject indicator of お前 (you) is so very interesting because I think based on the words used, it has a lot of romantic connotations. おまえ in modern use is consider rough/rude unless you are close to that individual.

お前のすべてを欲する [You are everything I lust for.]

お前のすべてを欲する
お前 (おまえ) - you (this was considered honorific language, but now it is very informal/rough/rude)
すべて - everything; all; the whole
欲する- to want; to desire
Note: Kanji means "longing, covetousness, greed, passion, desire, craving"

心在るが故に [Because of the heart]

Note: I think this part is so so important because it's like the speaker is coming to terms with themselves (i.e. Ulquiorra is the speaker) and their emotions. This is man who believes in nothing and nihilism, but because of the heart...

心在るが故に怒り[Wrathful because of the heart] 怒り(いかり) - anger; rage; fury; wrath; indignation

Note: kanji means "angry, be offended."

心在るが故に惰り[Slothful because of the heart] 惰り(あなどり) -this one threw me for a real doozy because Kubo is using the lazy kanji for a word that means "contempt, scorn" 侮り.

Note: kanji means "lazy, laziness." The furigana reading gives us "あなどり"

心在るが故に傲り [Prideful because of the heart] 傲り(おごり) - arrogance; haughtiness; conceitedness
Note: the kanji means "be proud." There are no subject indicators in all the lines except the last one so it is omitted in this translation, but I promise you it pays off!

心在るが故に奪い [Greedy because of the heart]
奪い (うばい) - to plunder; to grab; to snatch
Note: the kanji means "rob, take by force, snatch away, dispossess, plunder, usurp."

心在るが故に喰らい [Gluttonous because of the heart]
喰らい (くらい) - to bite at; to snap at; to nibble
Note: The word used is an action. The kanji means "eat, food." The word can also be translated as "devour." The speaker can also come off as a bit violent - "to snap at."

心在るが故に妬み [Envious because of the heart]
心 (こころ) - mind; heart; spirit
在る(ある) - to be; to exist; to live​
故 (ゆえ) - reason; cause; circumstances
妬み(ねた) - jealousy; envy - the 妬み is the bad kind of envy/jealous