For a map, I am trying to make a blaze rod named "Fire Rod" that gives the player fire resistance, but only when they hold it. To get this item, a player would have to stand anywhere on a 3x3 area with an armor stand in the middle named "testFR". The player has to stand there for 10 seconds to get it. If they step away, their wait time gets reset. Basically, the player has to stand on the area for 10 seconds straight. The item itself will also get /clear ed from the player after holding it for 10 seconds total.
I've already tried and made it work. The only issue is that it only works fine in singleplayer. In multiplayer, I'm encountering serious issues that are most likely based around @a selectors because when something happens involving the Fire Rod, both players get affected by the tags and this and that. Also, there's an issue that all the players online have to be standing ni the area to get the item, etc. My shot at making this is in this schematic for MCEdit, which you can download through this link so you can see what I'm trying to do better or help improve: https://www.mediafire.com/?6q3ebotvpg456n6
If anyone can help me, it would be greatly appreciated.