Fenrir Builds For Every Situation!

Fenrir is a versatile god that can play many roles. He is mainly played in the jungle and can do well in the aggressive support role too. He has a built in damage and lifesteal buff that allows helps his sustain and can allow him to easily outbox an ADC with the lifesteal build and allows him to do a lot of damage in the support role without building any power. His stun he gets from stacking his passive and using his 1 is important for ganks and for using in the support role to save your ADC and set up kills. It should also be used everytime you want to ult so you can guarantee hitting hit. After a while you may be able to bait out beads without even using your ult. Make sure to stack your passive before using Brutalize to clear so that you kill the small minions too. Pull enemies into your towers with your ult when you can. You can also simply stand still to make it easy for your teammates to hit their abilities and AA's when they are near. Mana pots are usually better than health pots because you have good sustain with your lifesteal, especially if you build the lifesteal build. Keep your passive stacked whenever you can and make sure you have it before ganking because it makes your abilities so much more useful.

Lifesteal Build

This looks to accentuate the lifesteal gained from his 2 and makes him partially an AA god that excels in fighting carries.
You start with Bumba's Mask and Achilles' Spear for good sustain, attack speed and clear and mobility. You want to build boots for the nice damage spike and the necessary mobility. Afterwards Devourer's Gauntlet so you can start stacking. It gives a lot of lifesteal and power and is really useful after you've stacked it. If you're behind, don't want to deal with stacks or want to build it later you can build Bloodforge. Jotunn's Wrath is really good for everything it gives. Frostbound Hammer helps you kill ADC's and gives you sticking power and health. The Executioner gives pen, attack speed and power and is a huge boost in damage. Midgardian Mail for survivability and to help even more with killing ADC's. You can switch the defensive items for different situations; for example if the other team is doing a lot of magical damage you might want to build Hide of the Urchin.

Power Jungle Build

This build is similar to the lifesteal build but I put in Transcendence for the great amount of power and mana that allows you to spam your abilities more. Titan's Bane is because you are more ability based. I change the defensive items to show off more defensive options and because power, pen and CDR benefit a more ability based build.

Support Build

On support Fenrir you have a lot of options. Early game you need a lot of health and defenses because you are really squishy. I also like Warrior Tabi because its power makes a huge difference in how much damage you do but you can also build Reinforced Greaves for extra defenses and CCR. Physical defense is the most important so you can take hits from the other ADC. This and the CDR and mana from Breastplate of Valor so you can use your ult often to get kills is why I built it first. Afterwards Soul Eater is really interesting because you get health and you and your ADC both get lifesteal. Then you just want to build more defenses and possibly CDR and get Sovereignty and Heartward Amulet to help your team survive and sustain, especially in team fights.