Telesma

Telesma is the power dwelling in the Phase known as Heaven Referred to as Telesma by the Golden Dawn and Golden-style cabals,  it is the source power for Angels of divine origin.

Etymology
Telesma is the English transliteration of the Ancient Greek word τέλεσμα (télesma, "payment"); and partly directly from Byzantine Greek τέλεσμα (télesma, "talisman, religious rite, completion"), ultimately deriving from τελέω (teléō, "to perform religious rites, to complete"), itself derived from τέλος (télos, "end, fulfillment, accomplishment, consummation, completion"). It is the origin of the word "talisman".

Principles
Telesma is a type of energy while exists within the phase known as Heaven, from which the entities known as angels are composed and manifested. Other types of power exist within different phases, but Telesma is the most prominent, being often used in Golden-style and modern Western magic.

The potency of telesma cannot be compared to mana. The human body cannot handle a large amount of telesma due to a difference of affinity, not a matter of potency. If the human body forcefully does absorb a large amount of telesma, the person would suffer severe damage as demonstrated when Acqua of the Back drained telesma from Archangel Gabriel. This further shows that Saints, even if they have undergone modification from God's Right Seat, cannot handle Telesma. However there are some people who can control telesma, like Leivinia Birdway, or with an object like the Curtana Original. There have been some cases where a human can possess telesma such as Sasha Kreutzev as a result of the Angel Fall incident. One side-effect of high telesma exposure on the human body is that a person becomes able to detect nearby Magic, experiencing pressure and a slight trembling when they are near to active spells or spiritual items.

Unlike mana, which is not initially aligned when produced, Telesma is aligned to one of the elements. Large concentrations can have highly dangerous effects on the real world, such as causing large tidal waves. Such phenomena is related to the element to which the Telesma is aligned. Dense concentrations of Telesma, such as that which covered London following the Overloading of the Curtana Original, also carry the risk of an explosion if magic is used inside them.

Angel Fall Arc
Due to the accidental casting of Angel Fall, Archangel Gabriel was summoned to the surface world in the form of Sasha Kreutzev (assuming the name Misha Kreutzev), accompanied by a large amount of Telesma. As a result of the incident, Sasha developed symptoms of high-concentration Telesma exposure and residual traces of Telesma were left in her body.

Orsola Aquinas Rescue Arc
During the events surrounding Orsola Aquinas and the Book of the Law, Index identified and interfered with Angelene's use of Telesma-infused coin bags based on the legend of St. Matthew.

Academy City Invasion Arc
On September 30th, at some point shortly before Vento of the Front's attack on Academy City, Sasha Kreutzev was carrying out research in the Phenomena Control and Reduction Reproduction Facility, looking into the symptoms which she had developed (recognized as similar to after-effects of housing high levels of Telesma), which had gathered the interest of others in the Russian Orthodox Church, not knowing about what had transpired during Angel Fall.

Later on, when trying to find a way to save Kazakiri Hyouka, who had been forcibly transformed into Fuse Kazakiri, Index Librorum Prohibitorum recognized similarities to the Golden-style method of constructing an angel by forcing Telesma into a 'container'. After witnessing Accelerator's black wings, Index thought that the field resembled Telesma but the substance was different.

Toaru Majutsu no Index SS: Stiyl
During the battle with Richard Brave's associates, Leivinia Birdway demonstrated her own use of Telesma with her 'summoned explosion' technique, wiping them all out.

Toaru Majutsu no Index SS: Mark Space
During the Blue Research incident, Mark Space and Wyss Winered made use of Wind and Earth Telesma respectively.

British Royal Family Arc
The events surrounding the British Halloween, the coup d'état by Carissa and the Knights of England, were focused on the Curtana, the sword which acts as the focus for a national spell woven into the structure of the United Kingdom and grants the royal wielder the power of Archangel Michael within the UK's territory, supplying Telesma to the royal wielder and the knights.

When Carissa returned to Buckingham Palace in order to tune the unstable Curtana Original, the Anglicans made use of a flash spell relayed from the Coven Compass in conjunction with the safety devices under the palace in order to send the Curtana Original's power out of control at 2:30 AM. The resultant discharge caused a significant loss of power from the sword, which would have taken a month to recover, and affected many of the spiritual items in the London, destroying three small churches and likely rendering half of the spiritual items in the palace useless. It also blanketed the capital in densely concentrated Telesma, such that using magic risked causing an explosion which would envelop the city, forcing both sides to wait for it to disperse.

World War III Arc
Following Fiamma's defeat, Archangel Gabriel gathered its scattered Telesma and reformed in a pure form. Seeking to restore its power and return to its proper place, it headed for the Arctic, with a line of Telesma forming between the two and the polar ice cap beginning to melt. Before the world was threatened by either the melting ice cap or a possible explosion of Telesma from Gabriel exceeding the capacity of its physical manifestation, Kamijou Touma managed to crash the falling Star of Bethlehem into the angel and make contact with his Imagine Breaker, sending it to back to Heaven.

Ichihanaran Festival Arc
During the conflict over Fräulein Kreutune, while fighting against Thor, Silvia exhibited her own use of Telesma via sigils drawn by her rope.

Magic God Othinus Arc
During the Manhunt for Othinus and Kamijou Touma, Marian Slingeneyer made use of Dáinsleif to cut away phases and bring forth calamities formed from the respective types of power within the corresponding phases, just as angels are manifested through condensed Telesma.

New Year's Eve Arc
On December 31st, when faced with a reanimated Anna Kingsford, direct Telesma control was one of the possibilities Anna Sprengel challenged her opponent to show.

Toaru Kagaku no Railgun SS2: Ability Demonstration Trip
During the incident at the Russian Shopping Center, Caliche I. Niknosh's magic cabal made use of a large-scale spiritual item in the form of a giant wheel snake, powered by Telesma aligned to Archangel Michael.