They both: provide a continuing advantage as long as the designation is maintained, apply to one player at a time, start the game applying to nobody, are granted explicitly by card abilities, can be "stolen" by dealing combat damage to the current designation-holder, are printed in supplemental sets rather than standard-legal sets, synergize with several cards in their sets, are narrow, directly interacting only with cards that mention them explicitly
There are a lot of essential Magic cards that cost 1 mana, and Mental Missteps option to be cast without any mana means the blue player will be countering spells before theyve even taken their first turn
If the Equipment is no longer on the battlefield as the job select ability resolves, explains WotC's Matt Tabak in the official FINAL FANTASY Mechanics article, you'll still create the Hero token, although you won't attach any Equipment to it. When my Reaper's Scythe enters the battlefield, its job select ability will trigger and put the trigger on the stack
It gives some defensive power to a deck looking to attack