Items are optional and based on what the enemy is made of.
For example if the enemy isnt fed u can build the tank items later, but if they are "fed" i recommend that u buy warden mail first only and spirit visage after, than u can go for some offense, but as i said its optional!

Start with gromp, than blue buff, red buff.
Farm the jungle as much as you can because you need to stack your devourer for more dmg.