variables:
    {kill.%player%} = 0
on join:
    if {kill.%player%} is not set:
        set {kill.%player%} to 0
on death:
    if attacker is a player:
        if victim is a player:
            add 1 to {kill.%attacker%}
            broadcast "&8> &6Gracz &c%attacker% &6zabil gracza &c%victim%&6!"
on right click on player:
    if name of clicked entity is "&bOdbierz zestaw":
        wait 2 ticks
        open chest with 1 rows named "&bOdbierz zestaw" to player
        wait 2 ticks
        set slot 0 of player's current inventory to wooden sword of unbreaking 1 named "&8Zestaw darmowy"
        if {kill.%player%} is bigger than 9:
            set slot 1 of player's current inventory to wooden sword of sharpness 2 named "&7Zestaw nowicjusza"
        if {kill.%player%} is bigger than 29:
            set slot 2 of player's current inventory to stone sword of unbreaking 2 named "&aZestaw podstawowy"
        if {kill.%player%} is bigger than 59:
            set slot 3 of player's current inventory to stone sword of sharpness 2 named "&2Zestaw giermka"
        if {kill.%player%} is bigger than 89:
            set slot 4 of player's current inventory to iron sword of unbreaking 3 named "&eZestaw najemnika"
        if {kill.%player%} is bigger than 119:
            set slot 5 of player's current inventory to iron sword of sharpness 3 named "&6Zestaw wojownika"
        if {kill.%player%} is bigger than 149: 
            set slot 6 of player's current inventory to diamond sword of unbreaking 4 named "&bZestaw gwardzisty"
        if {kill.%player%} is bigger than 179:
            set slot 7 of player's current inventory to diamond sword of sharpness 4 named "&3Zestaw króla"
        if {kill.%player%} is bigger than 209:
            set slot 8 of player's current inventory to gold sword of fire aspect 10 named "&cZestaw demona"

on inventory click:
    if inventory name of player's current inventory is "&bOdbierz zestaw":
        cancel event
        if clicked slot is 0:
            execute player command "kits darmowy"
        if clicked slot is 1:
            execute player command "kits nowicjusz"
        if clicked slot is 2:
            execute player command "kits podstawowy"
        if clicked slot is 3:
            execute player command "kits giermek"
        if clicked slot is 4:
            execute player command "kits najemnik"
        if clicked slot is 5:
            execute player command "kits wojownik"
        if clicked slot is 6:
            execute player command "kits gwardzista"
        if clicked slot is 7:
            execute player command "kits krol"
        if clicked slot is 8:
            execute player command "kits demon"