Charged Force Blast

You channel as much raw arcane power as you can muster into the crystal ball you hold in your hand, causing it to glow and pulse with light as cracks begin to form throughout the crystal. To release this energy immediately, you make a ranged spell attack, dealing 4d10 force damage on a successful hit, and the target must make a Strength saving throw or be pushed away from you by 10 feet for each round the spell was charged (minimum 10). You can also choose to hold your attack and charge the blast for as long as 10 rounds, during which time you must maintain concentration on the spell, and your speed becomes 0. Each round that you hold the blast, roll 1d100. On an 11 or higher, you add 1d10 to the force damage the blast will deliver when you release it. On a 10 or lower, the crystal ball shatters, releasing the stored arcane power in a localized blast and ending your concentration on the spell, and all creatures within 5 feet of the crystal ball take force damage equal to half the number of d10 the spell would have delivered if it had been released instead of failing.