BNHA’s author often names his characters with some relevance to their Quirk, and like one of the other ppl who also replied to ur post, I like to do the same. (readmore for length)
e.g Bakugou: Katsuki's name is composed of "爆" (baku) from "爆破" (bakuha lit. "explosion") and "勝" (ka(tsu)) from "勝つ"(katsu lit. "to win"). (source bnha wiki) So his name is literally his Quirk, “Explosion,” plus just.. “win.”
Iida’s is terrible. Tenya's name comes from "韋駄天" (idaten), meaning "great runner". "哉" (ya) is a final exclamatory particle. (source bnha wiki) So HIS name is literally a PHRASE, “What a good runner!” or something like that.
Also, fucking Tetsutetsu Tetsutetsu. Tetsu is steel, and his name is composed of four different Kanji that can be pronounced as tetsu.
Canon examples aside, that other commenter also mentioned jisho.org, which is a site I also use and find very useful. You could type an english word in the search bar to find Japanese words for it, and add “ #kanji ” if you’re looking for kanji specifically. If you can’t read hiragana and katakana, you can just copy/paste the characters listed under “kun” and “on” into google translate to see how it’s pronounced (see below; what’s listed under “kun” and “on” lists the various pronunciations for the kanji character).
( ⚠ ...Note that I’m a huge amateur in Japanese so there may be mistakes on this post, especially past this point...! ⚠ )
It looks like 蛇 can be pronounced hebi, jya, da, i, or ya?
黥: Irezumi, kei, gei
*The word “tattoo” is usually written like this 入れ墨 instead, but 黥 is another form of it according to jisho.org
So with 蛇黥 (snake tattoo), you could have it pronounced as any combination of the two: Yakei, Jyakei... Seems hard to make a good-sounding name from these two though.
‾\_(ツ)_/‾ Just an example using kanji that are relevant to your character. Some more...
中: naka, uchi, ata(ru), chuu
心: kokoro, gokoro, shin (This is the shin in Shinsou’s name, because he controls people’s hearts/minds)
煙: kemu(ru), kemuri, kemu(i), en
This is kind of just if you want to go hardcore Horikoshi though. I could try to help more if you really wanted to do that. Otherwise if it seems like a pain in the ass you can totally just ignore this post ( ͡° ͜ʖ ͡°)b