Explain how a fed Pyle can reach over 700 execution amount
That's pretty much the base damage on his ult at later levels. He can get his ult damage to well over a thousand and over 2000 with a cheesy build. I know, it's broken af.
does that mean regardless of armor amount it's useless? Your saying if I have infinity plus one armor it still goes through? Like I said it might as well be true damage instead.
No your armor is not useless. Your armor becomes irrelevant if your health drops low enough and your armor makes it harder for your health to fall that low, which means the armor is still useful. If the damage was straight up true damage, it would be used as a massive aoe ability at the start of the fight instead of as an execution because it would offer more value that way by ending the fight before it begins. Now that it's physical damage (and it actually does 50% of the ult damage if the target is above the health threshold), the damage above the threshold is very low.