SSS 2 - The Last Fortress

The Challenge:   Destroy the artillery as fast as possible and the lowest amount of power, with only Tier 1 and Tier 2 cards. XL Units are not allowed. 
Ranking:              Playtime * 10 + Power used * 0,1 (tie break 1. Playtime tie break 2. Power)
Starting power:    1000
Starting Orbs:       2xFire 2xFrost 2xNature 2xShadow
Max time:             3 min
Difficulty:             Standard
Map:                    SSS#2 - The Last Fortress (Community Map)
Note:                   Around the artillery is a anti flying aura, as well as a slowdown aura