Question: Besides the Holy Roman Emperor, who was also considered the a universal power or the pontifex Maximus?

Context articles: Roman emperor
Lex Ogulnia
Pope
Publius Licinius Crassus Dives (consul 205 BC)
Via Labicana Augustus
Rex Sacrorum
List of Pontifices Maximi
Pontifex Maximus
Universal power
Quintus Mucius Scaevola Pontifex

The Roman emperor was the ruler of the Roman Empire during the imperial period (starting in 27 BC).
 The emperors used a variety of different titles throughout history.
 Often when a given Roman is described as becoming "emperor" in English, it reflects his taking of the title "Augustus" or "Caesar".
 Another title often used was "imperator", originally a military honorific.
 Early Emperors also used the title "princeps" (first citizen).
 Emperors frequently amassed republican titles, notably "Princeps senatus", "Consul" and "Pontifex Maximus".
The lex Ogulnia was a Roman law passed in 300 BC.
 It was a milestone in the long struggle between the patricians and plebeians.
 The law was carried by the brothers Quintus and Gnaeus Ogulnius, tribunes of the plebs in 300 BC.
 For the first time, it opened the various priesthoods to the plebeians.
 It also increased the number of pontifices from five to nine (including the pontifex maximus), and led to the appointment of Tiberius Coruncanius, the first plebeian pontifex maximus, in 254 BC.
 The law further required that five of the augurs be plebeians.
The pope (Latin: "papa" from Greek: πάππας "pappas", a child's word for "father"), also known as the pontiff (from Latin "pontifex Maximus" "greatest bridge-builder"), is the Bishop of Rome, and therefore ex officio the leader of the worldwide Catholic Church.
 The primacy of the Roman bishop is largely derived from his role as the purported apostolic successor to Saint Peter, to whom Jesus is supposed to have given the keys of heaven and the powers of "binding and loosing", naming him as the "rock" upon which the church would be built.
 The pope is also head of state of Vatican City, a sovereign city-state entirely enclaved within Rome.
 The current pope is Francis, who was elected on 13 March 2013, succeeding Benedict XVI.
Publius Licinius Crassus Dives Pontifex Maximus (died 183 BC) was consul in 205 BC with Publius Cornelius Scipio Africanus (Scipio Africanus Major); he was also Pontifex Maximus since 213 or 212 BC (until his death), and held several other important positions.
 Licinius Crassus is mentioned several times (sometimes as Licinius Crassus or as Publius Crassus) in Livy's "Histories."
 He is first mentioned in connection with his surprising election as Pontifex Maximus, and then several times since in various other capacities.
The Via Labicana Augustus is a sculpture of the Roman emperor Augustus as "Pontifex Maximus", with his head veiled for a sacrifice.
 The statue is dated as having been made after 12 BC.
 It was found on slopes of Oppian Hill, in the Via Labicana, in 1910.
 It is now in the Palazzo Massimo alle Terme at the National Museum of Rome.
In ancient Roman religion, the rex sacrorum ("king of the sacred", also sometimes rex sacrificulus, "[one who makes] offerings made by the king") was a senatorial priesthood reserved for patricians.
 Although in the historical era the "pontifex maximus" was the head of Roman state religion, Festus says that in the ranking of the highest Roman priests ("ordo sacerdotum"), the "rex sacrorum" was of highest prestige, followed by the "flamines maiores" ("Flamen Dialis", "Flamen Martialis", "Flamen Quirinalis") and the "pontifex maximus".
 The "rex" was based in the Regia.
The Pontifex Maximus was chief priest of the "Collegium Pontificum" ("College of Pontiffs") in ancient Roman religion.
 The names of "Pontifices Maximi" for the Roman Republic are listed below as known.
 The last Pontifex Maximus of the Republican era was Lepidus, the triumvir.
 Upon his death, Augustus acquired the office, consolidating an additional source of power and authority for the "princeps".
 In the Imperial era, it was customary for the emperor to serve as Pontifex Maximus.
The Pontifex Maximus (Latin, literally: "greatest pontiff" or "greatest bridge-builder") was the high priest of the College of Pontiffs ("Collegium Pontificum") in ancient Rome.
 This was the most important position in the ancient Roman religion, open only to patricians until 254 BC, when a plebeian first occupied this post.
 A distinctly religious office under the early Roman Republic, it gradually became politicized until, beginning with Augustus, it was subsumed into the Imperial office.
 Its last use with reference to the emperors is in inscriptions of Gratian (reigned 375–383) who, however, then decided to omit the words "pontifex maximus" from his title.
 Although the most influential office within Roman priesthood, the "pontifex maximus" was ranked the fifth in the ranking of the highest Roman priests ("ordo sacerdotum"), behind the "rex sacrorum" and the "flamines maiores" ("Flamen Dialis", "Flamen Martialis", "Flamen Quirinalis").
In the Middle Ages, the term universal powers referred to the Holy Roman Emperor and the Pope.
 Both were struggling for the so-called "Dominium mundi", or world dominium, in terms of political and spiritual supremacy.
 The emperor and the pope maintained their respective authorities through diverse factors such as territorial dispersion, low level of technic and productive development in feudal mode of production, and social and political tendency of feudalism to decentralization of power.
Quintus Mucius Scaevola Pontifex (died 82 BC) was a politician of the Roman Republic and an important early authority on Roman law.
 He is credited with founding the study of law as a systematic discipline.
 He was elected Pontifex Maximus (chief priest of Rome), as had been his father and uncle before him.
 He was the first Roman Pontifex Maximus to be murdered publicly, in Rome in the very Temple of the Vestal Virgins, signifying a breakdown of historical norms and religious taboos in the Republic.