PoE FDL42 builds

Been trying to build a Storm Brand Raider for HCSSF because of the following synergies: - Onslaught gives MS and damage - Frenzy Charges double dip with More Damage and Cast Speed - Easy acces to Spell Suppression & Elemental Ailment Avoidance - Can path through Armour and Evasion nodes on my way to the Brand Nodes - Can path to a lot of Mana Reservation Efficiency However I seem to hit a ceiling in both damage and survivability. Especially Damage. I'm looking for a secondary skill that could boost single target, but I don't see it. Tried Lightning Spire