In voluntāte Deī is a Latin equivalent of the English phrase "in God's will." The prepositional phrase translates literally as "in (the) will of God" in English. The pronunciation will be "een WO-loon-TA-tey DEY-ee" in Church Latin and in classical Latin.
Di Immortales is actually Latin. It means "O ye immortal gods" which can be used similarly to the English phrase "my goodness" or "goodness me."
"He" is English is the personal pronoun is in Latin.
The verb est in Latin is "is" in English.
Testamentum in Latin is "testament" or "will" in English.
"Short" in English is brevis in Latin.
"Mind" in English is mens in Latin.
Quī in Latin means "what" or "which" or "who" in English.
M in Latin is "1,000" in English.
Infernus in Latin is "hellish" in English.
"Family" in English is familia in Latin.
"Life" in English is vita in Latin.
"Humility" in English is humilitas in Latin.