Instead of using a periodical to remove 1 from the variable, just do it in the "on damage" event.

Code (Skript):

1. loop 10 times:
2.     wait 1 second
3.     remove 1 from {qal::%victim%}
4.     remove 1 from {qal::%attacker%}

Just add something like that, but do a check so that if the on damage is triggered again, it doesn't continue running that loop and restarts it.

 

It really doesn't lag, I've had 45 people on a server looping all of them more than once a second, and I managed around 19.85 TPS on a non dedicated server. I wouldn't worry about it.

 

You can fix your issue by using the Skript expression: "difference (between|of) %object% and %object%", it basically checks the difference between two values.

Code (Skript):

1.  
2. on damage:
3.     if victim is a player:
4.         if attacker is a player:
5.             set {qal::%victim%} to now
6.             set {qal::%attacker%} to now
7.             if {victim::%attacker%} is not set:
8.                 set {victim::%attacker%} to "%victim%"
9.                 stop
10.             else:
11.                 if {victim::%attacker%} is not "%victim%":
12.                     set {victim::%attacker%} to "%victim%"
13.                     stop
14. on quit:
15.     if difference between {qal::%player%} and now is less than 10 seconds:
16.         kill player
17.        
18. on command "/spawn":
19.     if difference between {qal::%player%} and now is less than 10 seconds:
20.         message "&cYou are currently in combat and can't execute that command."
21.         cancel event
22.        
23. on command "/home":
24.     if difference between {qal::%player%} and now is less than 10 seconds:
25.         message "&cYou are currently in combat and can't execute that command."
26.         cancel event
27.        
28. on command "/hub":
29.     if difference between {qal::%player%} and now is less than 10 seconds:
30.         message "&cYou are currently in combat and can't execute that command."
31.         cancel event
32.        
33. on command "/lobby":
34.     if difference between {qal::%player%} and now is less than 10 seconds:
35.         message "&cYou are currently in combat and can't execute that command."
36.         cancel event
37.        
38. on command "/back":
39.     if difference between {qal::%player%} and now is less than 10 seconds:
40.         message "&cYou are currently in combat and can't execute that command."
41.         cancel event
42.  

 

Here's a more efficient form of the script:

Code (Skript):

1.  
2. on death:
3.     clear {qal::%victim%}
4.     clear {qal::%attacker%} #You may want to remove this line to accommodate for PvP w/ more than 2 players
5.  
6. on damage:
7.     if victim is a player:
8.         if attacker is a player:
9.             set {qal::%victim%} to now #This is now a time variable, which will make this script much more efficient
10.             set {qal::%attacker%} to now #This is also a time var now
11.             if {victim::%attacker%} is not set:
12.                 set {victim::%attacker%} to victim #This can just be 'victim' rather than '"%victim%"'
13.                 stop
14.             else:
15.                 if {victim::%attacker%} is not victim:
16.                     set {victim::%attacker%} to victim
17.                     stop
18.  
19. on quit:
20.     if difference between now and {qal::%player%} is less than 10 seconds: #Changed since we're using a time var now
21.         kill player
22.  
23. on command "/spawn":
24.     if difference between now and {qal::%player%} is less than 10 seconds:
25.         message "&cYou are currently in combat and can't execute that command."
26.         cancel event
27.  
28. on command "/home":
29.     if difference between now and {qal::%player%} is less than 10 seconds:
30.         message "&cYou are currently in combat and can't execute that command."
31.         cancel event
32.  
33. on command "/hub":
34.     if difference between now and {qal::%player%} is less than 10 seconds:
35.         message "&cYou are currently in combat and can't execute that command."
36.         cancel event
37.  
38. on command "/lobby":
39.     if difference between now and {qal::%player%} is less than 10 seconds:
40.         message "&cYou are currently in combat and can't execute that command."
41.         cancel event
42.  
43. on command "/back":
44.     if difference between now and {qal::%player%} is less than 10 seconds:
45.         message "&cYou are currently in combat and can't execute that command."
46.         cancel event
47.  
48. on login:
49.     if difference between now and {qal::%player%} is greater than 10 seconds:
50.         clear {qal::%player%} #Clears the unnecessary stored value
51.  

--- Double Post Merged, Feb 27, 2017, Original Post Date: Feb 27, 2017 ---

Jinx!

 

you posted like 20 mins ago, don't bump...

 

Yep, remove the "clear {qal::%attacker%}" if you don't want players to get unflagged right after killing someone. That way, that can't kill one player to escape another. But that also means they'll have to wait 10 seconds after killing someone to do anything, so your call.

I don't think those entity errors will be problem since you'd want the PvP vars to reset after a restart anyway. But if it does cause issues, set the vars to 'uuid of victim' instead, as that will be saved through a restart.

 

Nah, there isn't any way as far as I'm aware.