Arcane Blast also raises the cost
According to the demo tooltip, Arcane Blast strengthens other spells while increasing the mana cost of subsequent Blasts. Another damaging spell consumes the effect. Repeated Blast casts are therefore not a neutral default: monitor mana and decide when to transfer the accumulated benefit to another spell.
Missile Barrage creates a decision point
Missile Barrage can trigger from Arcane Blast and certain spells from other schools. In the demo it accelerates the next Arcane Missiles channel and removes its mana cost. Respond to the proc, but do not assume one universally best rotation before practical comparisons are available.
A damage cooldown still needs preparation
Arcane Power increases both damage and mana cost in the demo. Plan around the target’s remaining life, your mana and whether you can stand still. Presence of Mind can make an eligible spell instant; its value also depends on movement.
Your first test build
Explore the route to Arcane Blast and Missile Barrage in the calculator. Then compare choices affecting mana, threat and resistance to spell pushback. Equipment rankings, hit requirements and final burst sequences need sufficient test data before publication.