Zadkiel or Hesediel is the archangel

Archangel

An archangel is an angel of high rank. Archangels are found in a number of religious traditions, including Judaism, Christianity and Islam. Michael and Gabriel are recognized as archangels in Judaism and by most Christians. Michael is the only archangel specifically named in the Protestant Bible...

 of freedom, benevolence, mercy

Mercy

Mercy is broad term that refers to benevolence, forgiveness and kindness in a variety of ethical, religious, social and legal contexts.The concept of a "Merciful God" appears in various religions from Christianity to...

, and the Patron Angel of all who forgive. Also known as Sachiel

Sachiel

In kabbalistic and Christian angelology, Sachiel is an archangel of the order of Cherubim. The meaning of his name is given as "the covering of God" and he is associated with the Zodiacal sign Sagittarius, the weekday Thursday, wealth and charity. While in most sources Sachiel presides over...

, Zedekiel, Zadakiel, Tzadkiel, Zedekul and Hesediel. Rabbinical tradition considers him to be the angel of mercy.
In rabbinic writings Zadkiel belongs to the order of Hashmallim

Hashmallim

Hashmallim are an angelic entity in both Judaism and Christianity.They appear in the Hebrew Bible in Ezekiel 1:4Hashmallim occupy the fourth rank of ten in Maimonides's exposition of the Jewish Angelarchy....

 (equated with the Dominations or Dominions), and considered by some sources to be chief of that order (others sources name Hashmal or Zacharael). In Maseket Azilut Zadkiel/Hesediel is listed as co-chief with Gabriel

Gabriel

In Abrahamic religions, Gabriel is an Archangel who typically serves as a messenger to humans from God.He first appears in the Book of Daniel, delivering explanations of Daniel's visions. In the Gospel of Luke Gabriel foretells the births of both John the Baptist and of Jesus...

 of the order of Shinanim. As an angel of mercy, some texts claim that Zadkiel is the unnamed Biblical Angel of the Lord

Angel of the Lord

The Angel of the Lord is one of many terms in the Hebrew Bible used for an angel. The Biblical name for angel, מלאך mal'ach, which translates simply as "messenger," obtained the further signification of "angel" only through the addition of God's name, as The Angel of the Lord (or the Angel of...

 who holds back Abraham

Abraham

Abraham , whose birth name was Abram, is the eponym of the Abrahamic religions, among which are Judaism, Christianity and Islam...

 to prevent the patriarch from sacrificing his son, and because of this is usually shown holding a dagger. Other texts cite Michael

Michael (archangel)

Michael , Micha'el or Mîkhā'ēl; , Mikhaḗl; or Míchaël; , Mīkhā'īl) is an archangel in Jewish, Christian, and Islamic teachings. Roman Catholics, Anglicans, and Lutherans refer to him as Saint Michael the Archangel and also simply as Saint Michael...

 or Tadhiel or some other angel as the angel intended, while others interpret the Angel of the Lord as a theophany

Theophany

Theophany, from the Ancient Greek , meaning "appearance of God"), refers to the appearance of a deity to a human or other being, or to a divine disclosure....

.

Zadkiel is one of two standard bearers (along with Jophiel

Jophiel

The Archangel Jophiel is also known as Iophiel, Iofiel, Jofiel, Yofiel , Youfiel and Zophiel .-In Jewish and Cabalistic lore:...

) who follow directly behind Michael as the head archangel enters battle. Zadkiel is associated with the color violet

Violet (color)

As the name of a color, violet is synonymous with a bluish purple, when the word "purple" is used in the common English language sense of any color between blue and red, not including either blue or red...

.

In Jewish mysticism

Mysticism

Mysticism is the knowledge of, and especially the personal experience of, states of consciousness, i.e. levels of being, beyond normal human perception, including experience and even communion with a supreme being.-Classical origins:...

 and Western ritual magic, Zadkiel is associated with the planet

Planet

A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

 Jupiter

Jupiter

Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

. The angel's position in the Sephirot is fourth, which corresponds to mercy.