How can you do it that you loop all players but eg only the one who is above a certain y-cord should be looped. Here:
every 2 ticks in "ffa":
loop all players:
if loop-player is in world "ffa":
if y-coord of loop-player is bigger than 8:
if slot 0 of loop-player is a diamond sword:
stop
else:
equip loop-player with all iron armor of unbreaking 2
stop
Should be that is above a certain y-cord.
Insert coordinate as an additional condition?
The scripting language is terrible, by the way, learn something clever that will also bring you something in the future.