introduction:
this olaf and i think this is the best champion in the game because of his true damage and his overall ability
skills:
undertow
Olaf throws an axe into the ground at a target location, dealing damage to units it passes through and slowing their movement speed. If Olaf picks up the axe, the ability's cooldown is reduced by 6 seconds. , i really dont like this ability cause all of the other ones are way better
vicious strikes
Olaf's attack damage is increased, based on his health, and he gains massive lifesteal and spell vamp. this ability rocks the thing that keeps u alive at a sliver of hp
Reckless Swing
Olaf attacks with such force that it deals true damage to his target and himself. best dps to kill squishys and tanks
Ragnarok
Olaf is immune to disables, has increased armor penetration and reduces incoming damage best ulti ever makes u invinsible and at low hp with vicious strikes u will never die unless u get focused
runes
i pick it cause it helps u dish out dps
masteries
21/9/0 best for dps and sureviving
idems these idems help u deal mass dps and also stay alive with the lifesteal
skill sequence
Reckless Swing owns at early game so i max it out first then vicious strikes
because it helps late game take ur ulti whenever u can(6/11/16)
undertow is just there because its there
summoner spells
ghost is for catching up and killing champions and running away, exhaust is for slowing and blinding champions to win a fight

pros and cons
pros:
can stay alive at the last sliver of hp
deal mass dps if unaccounted for
strong early-mid-late game
all over awesome
cons:
walks slow