RA Conq/Joust beam mode

They're okay, not amazingly efficient but they can work. For example first build if you're going to pick up a Spear of Desolation late game, but pick up Chronos' Pendant after boots, you may as well get the Spear of Desolation early to make the most use of the flat penetration and swap your Mage's Blessing or Shoes of Focus for Chronos' Pendant or something else. Also in the first build Staff of Myrddin isn't a great pick up on him and it overcaps your CDR so you're better off with something else like Soul Reaver.

The solo build seems "fun" but really you need a lot more protections and can get a similar result without building so many pure damage options. With the current build I would take out Spear of the Magus and Staff of Myrddin; switch Magi's Cloak to a situational and add Breastplate of Valor, Void Stone and Mantle of Discord. The new order being as follows:

Warrior's Blessing > Shoes of the Magi > Warlock's Staff > Breastplate of Valor > Void Stone > Rod of Asclepius > Mantle of Discord > Rod of Tahuti

Although for that build order in Solo I think something more powerful would be to stack Book of Thoth and pick up Shoes of Focus with Breastplate of Valor for a lot of power and still being tanky.