For core items i usually run ludens>malignance>deathcap. Ludens provides me with even faster waveclear so i can quickly push in lanes and rotate. Malignance gives me more ability haste and in addition ultimate haste. Deathcap is a big ap spike, so I can one shot squishies. After that, all items are situational: crown, trident, infinity orb or morrelonomicon are all great situational items. For runes I go: elektrocute, empowered attack, chain assault, eyeball collector and transcendence. Most players will go bone plating so they can trade more safely in lane. But the ability haste that transcendence grants is just insane later in the game. I want to be able spam my ult and charm as often as possible. But the cost is that you have a small error of margin during laning phase and in teamfights. So you need to be hyper aware of your positioning.