When Janemba returns to the battlefield Xeno Trunks proceeds to transform into Super Saiyan God which shocks both Goku and Vegeta.
Trunks was shown becoming a super saiyan in the 1 hour special titled 'Dragon Ball Z: The history of Trunks'. The transformation was triggered when trunks went to the city where Future Gohan and the androids were fighting and found Gohan lying face down in a pool of blood.
In dragon ball super, during the battle with Zamasu & goku black alongside Goku & Vegeta, Trunks transforms passed super saiyan 2. I believe he showed glimpses of being the legendary super saiyan of his timeline. Its possible broly never existed in trunks' future timeline.
As far as I know, none of them will ever go Super Saiyan Blue. Goten and Trunks are a given, since they're not in any shape or form ready for such training/process to achieve the form.
Clearly, training with Vegeta allowed Future Trunks to take in essence of God Ki into his body, allowing him to transform when the time came.
After becoming a God of Destruction candidate, Trunks became even more powerful than ever before to the point of gaining all the abilities of a God of Destruction. It is stated by Beerus that Trunks has the potential to become just as powerful as he is.
While Super Dragon Ball Heroes and its subsequent adaptations in manga and anime are not considered part of the main canon, Trunks' transformation marks the first time a Saiyan-human hybrid is seen achieving the form in any form of media from the franchise.
While no ritual was done for Future Trunks, this does set the precedent that God Ki can evolve from regular Ki. It's entirely possible that, in the heat of the moment, Trunks simply became divine in nature.
Trunks never had god ki. He went into rage mode. He is very powerful and always has been but he does not have god ki, not even temporarily.
Hepta- is a combining form used like a prefix meaning “seven.” It is used in a number of scientific and other technical terms.
appearance is the suffix of appear..
The prefix circum-, which means “around,” is featured in several commonly used English words.