It has nothing to do with the number of trust. It's based on activity points.
Here's the link for forum ranks --> https://bitcointalksearch.org/topic/forum-rankspositionsbadges-what-do-those-shiny-coins-under-my-name-mean-178608. Go on and read that sticky. It will help you a lot to understand how someone ranks up. But you have to understand that merely posting will not get you rank up quickly. Ranking up is based on activity points and it is given every 2 weeks. So if you want to be Legendary someday, It will take a lot of your time to achieved that Rank. Goodluck to you and hope you enjoy your stay here in the community.
Thanks it is really helpful for me as a beginner i am locking the topic thanks for your time