Is the abundance the titles of the Imam of the Age because of the profusion of his personal, spiritual, and physical characteristics, or is it on account of the vastness of his reformative actions?
It is understood from the traditions that the blessed names of the twelfth Imam (may Allah hasten his return) are: Qa’im (The Riser), Mahdi (The Guided), Gha’ib (The Absent), and Hujjat (The Proof). In addition, various traditions mention him with titles such as Hujjatullah (The Proof of Allah), Khalifatullah (Caliph of Allah), and al-Qa’im (The Riser). The reason for the abundance of his titles is the same two factors mentioned above. Of course, out of these titles, some are more well known than others.
It is possible that conditions in a particular time cause people to pay greater attention to one of these titles or qualities or that a particular aspect of the issue be discussed more, and consequently speakers, writers, and poets give more attention to that title or aspect. This is similar to the “most beautiful names” (al-asma’ al-husna) of Allah, in which individual circumstances or prevailing conditions cause people to give more attention to one of those names and call Him by it, such as “Al-Shafi” (The Healer), “Al-Salam” (The Security), “Al-Hafiz” (The Protector), or “Al-Raziq” (The Sustainer). And this is not to mean that the remaining “most beautiful names” do not have a reason for being attributed to Allah.
Thus, each of the names and titles of the Imam of the Time (may Allah hasten his return) refer to one of his qualities or actions, and most of them have been mentioned in traditions that broach the actual issue of the twelfth Imam and his reappearance. That is, that personage was well known by these names and titles years before he himself or his father were even born.
Regarding the fact that the twelfth Imam is the same as the Mahdi and the Mahdi is no different from the twelfth Imam, eminent Sunni scholars agree with the Shi‘a. For this very reason individuals like Abu Dawud - author of the book Sunan (prophetic character) - have narrated traditions of the twelve Imams, and among his titles, his being promised by the prophets and his personal excellencies and genealogy are referred to.