Misagh
Misagh is based on Arabic-Persian lexical roots; while it appears in Persian usage as a given name, its root ideas (pledge, signet) derive from Arabic vocabulary used across Persianate Muslim cultures.
No specific proper name 'Misagh' does not appear as a personal name in the Qur'an; related root words for oaths and covenants (e.g., mīthāq / ميثاق) do occur, but Misagh as a given name is a post-Qur'anic onomastic usage.
Yes. Misagh is attested in modern Persian-speaking communities (Iran, Afghanistan) as a rare and formal personal name, often chosen for its poetic sense of fidelity.
Misagh carries a solemn, formal tone with connotations of trust, oath, and honor; it is poetic rather than colloquial.
Yes. While most familiar in Persianate contexts, the meaning is intelligible in Arabic and other Muslim languages and can be used wherever Persian-Arabic cultural influence is present.