Spell Damage ( Garen q)

Do you have a team that looks at damage dealt ? I get burst down without any reason these days. Today, I got burst down by a Garen. He dealt 910 damage with decisive streak (One time). I just calculated damage because 910 was a bit too much.

He was lvl 17

• So he had 129 ad

• Runes : 32.56 armor pen 91.28 armor pen 91 armor 90.7 armor For a total of 19.2 armor penetration and 15.3 armor.

• Masteries : Sorcery : 2,0% ability damage Double edge sword : 3.0% damage Natural talent : 9.45 ad Bounty Hunter (10 kill) : 10% damage Battering Blows : 7% armor penetration Fervor of Battle : 14 (his q was is first AA)

• Item Attack Damage : 65 + 50 = 115 Armor pen : + 20

*Buff : Infernal Drake 8% ad No baron or elder

Attack Damage : 273,726 (+14 from fervor) Armor penetration : 39.2 and 7% Damage : 115%

Lee sin lvl 16 : Armor 77.8 Item : +50 armor Let's skip runes and masteries since it is minor except the 1.5 additionnal damage from double edge sword

77.8 + 50 = 127.8 armor

So I have 7% less because of armor penetration which is about 8.946 armor. 127.8 - 8.946 = 118.854 armor Flat armor penetration 118.854 - 39.2 = 79.654 armor Which means I take : 100/(100+79.654) = 0,56 physical damage taken

Garen deals 140% ad + 130 with q. (287,726*1,4 +130) = 532,82 physical damage And I take 56% of this damage which is : 298,38 damage.

So he did about 3 times the normal damage with one Q. Since I almost instantly died, I don't think the error is only on the death recap. Do you have explanation ? I didn't make a research to check if it is Garen Q, the damage reduction, the armor penetration, the % damage but there is something wrong somewhere.