Fenrir DPS

Probably not every game...and in a teamfight mode (non-Conquest), you're more likely to be fighting more than one enemy at a time. Some protections can prevent some deaths, and while you're alive, you can continue doing more damage, even if your DPS is a bit lower due to picking up some prots.

Your four most recent matches:

https://smite.guru/match/censored/rbH5QqYAm
https://smite.guru/match/censored/8GHaEzygb
https://smite.guru/match/censored/k4HXNB7kD
https://smite.guru/match/censored/dxHEW8dz8

I reference these matches of yours to make some points, not to insult or put down. Firstly, no one gets top frag every game. Hyperbole is fine if you're trying to make a point, but it's quite the exaggeration here.

Top frag I assume, when you DO, is maybe top kills, not necessarily top damage. In teamfight modes, this means you might be getting some last hits (where you didn't deal the majority of the damage). In any case, none of these last 4 games saw you get top kills or top damage. There is an underlying reason for this in your build set, and if you take the time to open your mind to other ideas and reasons behind using proper builds with important stats.

Bloodforge can be fine, but as a 2nd item, it's not great due to the high price. Later, it can be nice especially when you're squishy if you're able to consistently get kills, as the shield will help. But again, pointing out it's a better late-game item when you do pick it up.

Devourer's Gauntlet not only needs stacks to get max effectiveness (which you get from god/minion kills), but also the lifesteal only works on basic attacks. I can almost guarantee you're doing more damage with your abilities than your basics, though as your account is newer, I wouldn't be surprised if other newer players might get caught and become sitting ducks for you and your team. In any case, it's not a good item for him.

Then you've got Malice, Heartseeker, and Arondight. I'm going to assume you picked these because you looked at high power or something. For Malice, having only 25% crit in your build doesn't make crit very reliable. Most crit builds have at least 2 crit items, or in rarer cases, just one with Rage since the crit chance is much higher.

Heartseeker and Arondight are both mostly ability-based items. HS is a great item for him, and is in a good position. It also represents the only penetration of any type in your entire build, which hurts your damage output potential. Arondight is perhaps less needed for Fenrir because when he ults, he's usually bringing an enemy back to his team to finish off, so doesn't really need the chase potential.

Really, your best "normal" bet is to go with the mace tree for damage...Warrior, Jotunn's, Crusher or Brawler's, Sledge, Heartseeker, Titan's Bane or Serrated at the end, perhaps. Sledge here represents a bit of survivability due to the high health and situational passive prots, while still providing decent power for more damage. You could pick it up or leave it, build it earlier or later in the build if you wanted, or get a different bruiser item if you so preferred, but you might find your survival increases noticeably if you get at least 1 prot item. You can't deal damage if you're dead.

In any case, this build is not suggested, though you can make it work against newer players / lower level competition, or if your skill level is very high. You're massively missing penetration, your build structure is concentrating on basic attacks for a god that relies mostly on abilities, and your build order hurts your power curve. A lot of things that could be improved here.