The combo for this build is to cast magnetize then breach surge and shoot them with the alt fire of [Cedo] (Build link : PH) or apply a DOT to proc surge sparks. Due to surge sparks being projectiles they scale the bubble damage rapidly which then proc more sparks in an exponentially increasing damage loop.

you will need to position yourself near or behind your bubbles to avoid enemy fire and use your polarise to regain shield gating when needed (and also create space via the CC), it is also an alternative to the [Cedo] as the proc of damage it causes scales with enemies and the shards it drops also empower the magnetize bubble. so you can instakill groups with just those 3 ability casts.

WARNING - if you combo a large enough group it WILL freeze your game for 1-3s before the enemies explode with damage numbers ranging from 100's of millions to damage cap.

be ready for pain tho as you need click A LOT of button pressing with this build, (I have to take 5-15m breaks during endurance runs to give my fingers a break every 1-3h.

You can also swap [Enemy Radar] for a [Brief Respite] and use [Augur Secrets] instead of [Streamline], this allows magnetize to scale quicker (even tho it's almost instant as it stands) and to use shield gating without CC'ing enemies with your polarise which is good/bad situationally.