Poppin' off that True Damage

During my last game of league i notice the enemy team was stronger than normal, while inspecting the Death Re-Cap i notice that the enemy champions were dealing Pure True Damage in most situations. i noticed it first on Kled and it continued after a few deaths then i saw it on Akali who did a whopping 2.8k true damage from her autos with an ap build. then it was on Kog'Maw and it switch off from there, however, it didnt occur on different champions during the same attack. I have no thoughts of what might be causing it since nothing seemed unusual except the excessive damage output. Need more info? Please message me.