I'm really struggling with Gold Wave 7 as arcane. My normal tactic on earlier waves is to frost nova and then sheep monkeys, positioning so they take the summoned amber, then pewpew healer with glyphed counterspell as the interrupt. Clearing up whatever's left is normally straightforward. There's normally time to eat to full mana and rune of power before the next wave hits. But I'm a long way short with the monkey, healer, guardian, amber summoner and banshee so far.
Any hints would be welcomed.