Ult Dynamo Build by Sharky

The first 2 purchases of the lane phase Headshot Booster and High-Velocity Mag increase weapon damage and bullet velocity as dynamo has a low base velocity.

Next vitality items Extra Health and Sprint Boots for increased sustain and mobility.

Extra Charge and Extra Spirit for more damage and an extra Kinetic Pulse.

Lastly Mystic Reach for increased ability range and bullet resistance.

One of the few mid game purchases before saving for tier 4 items would be Swift Striker for increased fire rate and Kinetic Dash for more consistent mobility and added fire rate.

Lastly Bullet Resist Shredder to combo with Kinetic Pulse extra damage and Enduring Speed for movement speed resistance.

After purchasing all the mid game items saving for Refresher is crucial for this build, once it is bought the next options are Improved Reach on the Singularity for range increase and Warp Stone for mobility and damage which is important in closing gaps. 

As this build does not require alot of souls and farm the final purchase of this build Unstoppable to secure a longer duration Singularity allowing your team to captialize.

The best time to add Improved Bullet Armor and Improved Spirit Armor is situational depending how fast on enemy team scales but is usually purchased during the mid to late game.

Debuff Reducer or Debuff Remover are great options against teams with large amounts of debuffs and stuns, especially against Knockdown and Slowing Hex.

If not opting into armor an alternative would be Combat Barrier or Enchanter's Barrier.