Asyndeton is a list or a series in which no and is used at all, rather the items are separated by commas. Asyndeton has an effect that is quite different from polysyndeton’s. 

アシンデトンっちゅーのは"and"が全然使われへん時のことを言うんや。ポリシンデトンとはまたすんごい違った効果が生まれるんやで。

If the effect of polysyndeton is to slow the reader down, the effect of asyndeton is most often the opposite: to speed the reader up.

ここまで言うたらわかるやろ。ポリシンデトンはスローダウン。アシンデトンはスピードアップ効果や。

Notice that in the example the lack of and functions to speed up the sentence without distracting the reader/listener. Further, we get the sense that this list of adjectives (explicit, vivid, horrifying) could go on to further prove how terrible the lynchings were. Ex. Ida B. Wells, protest writer and speaker, used explicit, vivid, horrifying descriptions of lynchings to prove the need for whites to reinforce white hegemony was the real cause of most lynchings.

"and"がないと、読んでる人の気が散らんでさらさらっと読めるやろ。ほんでまた、ポリシンデトンの時とちょっと違うニュアンスではあるんやけど、これもまたその後にまだまだ続きそうな気がするんやな。

One of the most famous examples of asyndeton is attributed to Julius Caesar.

Ex. “I came, I saw, I conquered.” –Julius Caesar

中でもいっちゃん有名なんがジュリアス・シーザーの名言や。
「来たわ、見たわ、やったったわ。」ってやつやな。

Let’s briefly consider this example if there been a final and placed within it.
Ex. “I came, I saw, and I conquered.” –Julius Caesar
The impact of the statement isn’t nearly as strong. The flow was interrupted with the use of and, which slows down the reader and finalizes the list (meaning, Caesar didn’t do anything else). Notice the lack of and renders each element (each of the sentences) equal—the act of seeing and conquering are of equal weight (he completed both tasks with the same ease)—and suggests that the series is unfinished, thereby offering additional possibilities.

もしこれが「来たわ、見たわ、ほんでやったったわ」やったらなんかちょっと弱ない？"and"を入れてまうことでなんか流れが止まってまうし、「終わった」感が出てまうからシーザーが何も他にしてないみたいやろ。他にも色々やってるっちゅー話やで。ほんで「来た」「見た」「やったった（勝った）」ってのがそれぞれイコールな感じがするんや。シーザーは他の国とか領土に「行ったり見たりすること」と「戦争に勝つ」ことをおんなじぐらい楽勝でやったったんやっていう演出がされてるわけやな。おしゃれやな。

Veni, vidi, vici