You can use the deathCount scoreboard criterion.
Create a deaths scoreboard:
/scoreboard objectives add deaths deathCount
Then put the following in a repeating, unconditional, always active command block. This show all the players who have died the message "Lmao you suck".
execute as @a[scores={deaths=1..}] run tellraw @s "Lmao you suck"
As "Lmao you suck" is a JSON text component, you can customize the colour and make it bold/italic/underlined/strikethrough/obfuscated (just use a generator like this one).
Put this in a chain, conditional, always active command block that the previous command block is pointing towards to reset the counter:
scoreboard players set @a deaths 0