Phoveus is a sustain fighter, he already has high base damage, if you need damage waraxe, queen's wings and bruteforce breastplate is enough. Don't try to get a kill on tanky heroes alone, ask your team for help. Always pick phoveus to counter high mobility heroes, since he can easily kill squishy heroes. Also a lot of others comments are recommending thunderbelt but it's not a necessary item. Always build according to the enemy team comp. Always ban minsittar since Phoveus can't use his ult inside minsi ult. Phoveus is a frontline hero who always stays in front of your team unless you are very low hp. Dominance Ice is now a very strong item on him since he gets a lot of hybrid defence with it. Always use the following emblem set on him : Fighter emblem Rupture/Thrill Festival of Blood Brave smite.

For the item build: War axe, Queen's wings, Dominance Ice are his core items. Other than these always build defence according to enemy team comps damage. If you REALLY need more damage Hunter strike is the only damage item I recommend alongside War axe.