Predecessor Builds > Revenant > AP Carry Revenant

I'm a big fan of this build, it has a nice bit of everything to make running AP Carry Rev a good time.

Alchemical Rod + Soul Chalice
One of my favorite aspects of this build is the synergy between Alchemical Rod and Soul Chalice. The combination of these two items and their respective Font and Potent Font passives in addition to the 3.5% bonus magical power based off maximum mana now being combined into Font make it so that this build comes online with very quickly with very little gold invested just by diligent farming! When you do reach the 400 bonus mana cap on both items you'll gain bonus Physical & Magical damage, which will add a VERY nice punch to those Obliterate casts (even more so later on in the game), and the bonus physical damage also helps to ensure that Rev's basics aren't as "wet noodly" as they usually are when going the AP path. These two items also help to ensure that Rev doesn't have to worry about Mana and can freely and continuously cast his abilities without running low.

Spellbreaker + Timewarp
Both of these items are great on their own but really provide Revenant with some great utility against enemies. Spellbreaker allows Revenant the confidence to take on those 1v1 Reckoning fights knowing he'll be able to be protected from at least one ability which could be a deciding factor when dueling bursty Mages or CC heavy Heroes, even the likes of RMB's from opposing carries such as Kira or Murdock don't appreciate this shield. The shield is also useful for its bonus magical power while up, as well as providing you a moment longer to react to enemies diving you and allows you a chance to reposition with your blink or isolate yourself via Reckoning.
Timewarp is an amazing item that helps in so many ways! Firstly it gives a huge boost to your Magical Power allowing you to Obliterate even more things, additionally you build up even more Magical Power (as well as Physical Armor) through the Ferrumancer passive component which is always nice to have as you'll be frequently casting abilities to takedown enemies, so those stacks will stay fresh. And cast abilities you will because while Obliterate will eventually get to the point of having a near 3 second cooldown, the Chime passive will wipe 1 second from cooldowns every 8 seconds so your abilities come off cooldown even faster.

Advice
Stay on the backlines and target the enemy squishies. Tanks and Brsuisers won't appreciate your damage either but you can wipe squishies fairly quickly, and definitely within the Reckoning time limit. With Spellbreaker, Soulbearer, Reckoning, and your blink you become annoyingly hard to pin down so use those wisely to weave through fights and burst down the targets your team needs you to.