scoreboard players set .remove combo 21

execute if score .current combo matches 1 run scoreboard players set .multiplier combo 1
execute if score .current combo matches 2 run scoreboard players set .multiplier combo 2
execute if score .current combo matches 3 run scoreboard players set .multiplier combo 5
execute if score .current combo matches 4 run scoreboard players set .multiplier combo 7
execute if score .current combo matches 5.. run scoreboard players set .multiplier combo 10

scoreboard players set .remove_amount combo 20
scoreboard players operation .remove_amount combo *= .multiplier combo

scoreboard players operation @a combo -= .remove_amount combo