Datapack
KillStreakPack
make a working datapack for the version 26-2 that every time you kill A random Player you gain a speed level with a maximum of 4 levels and on the fourth kill u gain strenght 2 when you die however u loose the speed level and if u had the strenght effect u loose that fully
data/killstreakpack/functions/on_player_kill.mcfunction
scoreboard players operation @s ksp.killEvent = @s ksp.kill_player
scoreboard players operation @s ksp.killEvent -= @s ksp.kill_player_prev
execute if score @s ksp.killEvent matches 1.. run scoreboard players add @s ksp.streak 1
execute if score @s ksp.killEvent matches 1.. run scoreboard players operation @s ksp.streak %= #4 ksp.const
execute if score @s ksp.killEvent matches 1.. if score @s ksp.streak matches 0 run scoreboard players set @s ksp.streak 4
execute if score @s ksp.killEvent matches 1.. if score @s ksp.streak matches 1..3 run effect give @s minecraft:speed 999999 0 true
execute if score @s ksp.killEvent matches 1.. if score @s ksp.streak matches 4 run effect give @s minecraft:strength 999999 1 true
execute if score @s ksp.killEvent matches 1.. if score @s ksp.streak matches 4 run effect clear @s minecraft:speed