first of all..i would like to apologize for my bad english..

why do i play this warwick..because its supreme solo champ and in teamfights is great when somebody else is targeted..

I am not much of a masteries expert but this is how I play.
9-0-21

im going for the magic penetration skill in offense and cooldowns cuz your Q is one of the greater essence in early game.

first master your hungering strike,and if u got someone on low hp,from the first fight,take blood scent for extra speed.Then keep them on low hp by spamming heal..when you get to lvl 6 he is dead...
first..initiate with infinite durres or if you are standing near him use your Q then infitie durres then Q again and ignite for the end not even a mord can escape that..but you need to be carefull..dont underestimate your enemy..

but before you go in for the kill..always CHECK is there anyone ss on their team..because if you use ulti up and all of your mana..even if you kill your target..you will die..invane..

Best runes for ww hybrid are magic pen. becasue of his Q..
seals im not so sure of but i play it this way and doing great..and has taken me out of some serious **** situations..now i have changed them and have been playing mana reg/per lvl and hp/per lvl..you are not a tank..but you need them..
cooldown runes also for your skills..they re must cuz you will be spamming heal on them..

Your start would have to go something like this..first buy dorans ring..you will see why is that helpfull..(mana regen,ap,health) then if you like you cant take boots of swiftness instead of magin pen boots..first item get HEXTECH,then farm crips and go kill dragon if you can buy maladys then rageblade and so on..and when u fill up all the rest sell the dorans ring and buy frozen mallet..you now have huge attack speed so you can slow them and that might actully win you a teamfight..
you will usually get targeted first..if needed buy guardians..
do NOT go jungle early game..until you get hextech you are uslles in jungle but with this build i soloed baron and and didnt loose any hp or mana..but if you do try to do baron solo..make sure you HAVE the BLUE and the RED buff..its a must!!