This is my Tank/Mage WW-Build. I have 1 Thing to say: YOU'll never die if you build like this.

My runes are Tanky, too. BEcause you deal percentage damage with your q skill. I choosed Armor penetration marks and 1 quintensence for my ult because youve got the +20 Magic Pen Shoes wich make your q skill strong enough you dont need more magic pen, because of that. Seals with armor are alwys good for early game and if your team hasn't got a jungler you are able to jungle with that 13 Armor. Magic Resist per Level is good for mid and lategame wich gives you more magic resist because you wont normally buy Force of Nature.

My masteries are 9-0-21. I think you aren't squishy with that kind of runes, wich Ive chosen then you dont need the defensive-tree for more tenacity. And the cd-reduction on your q-skill and your ulti will be awesome with the utility-tree. :)

My Items are tanky, too. You'll need the tanky items because you play tank-ww :D. With the Sunfire-Cape, Thornmail and Abyssal Cepter youll deal additional Damage and you arent so squishy as you think :). With Spirit Visage youll heal you more qith your q skill and your ult.

I dont need more Attack SPeed than 40% because of that I skill Hunters Call only 1 Time. Skill your Q-Skill wehenever you can. It deals entirely Damage and heals you over so much its just EPIC ;D. BLood Scent is nice to skill because in all team fights will 1 person be low health and it gives you so much speed. Its good too to find low Persons in jungle and to incerept with your ult :D. And if you wanna kill someone in 1 vs 1 your attack row will be like this:
ULT->IGNITE->Q->W->Q->Q->Q...

Ignite is alwys a good Spell to have because it deals true damage and nice damage in early game. Ghost is justr epic with your E-skill because it gives you so much speed if 1-Person will be alive after a teamfight and you wanna incerept. Optional is Exhaust, Flash and Cleanse :)

MY Guide is tanky-undying-mage-warwick and Ihope you enjoyed it my english isnt good I know :D
I made this guide in 1 hour enjoy to play Tanky-WW and I hope youll kill as much persons as you can. :)