Epic moment spell with 3d6 damage per level for 300 sp and with 3 mins cool down? This is wai, or attempt for something as DDO quinness record?

Don’t know Celestial Bombardment’s cost and cool down with more rank, but 300 sp and 3 mins cool down are triple values then they was on Lamania.

Also this is only one divine destiny spell like ability, which isn't wisdom/charisma based, but only wisdom based. Why?