then just leave some defenses on it or use passive attack and defense artifacts on it.

those are semi hard to get, and usually people will use those on one planet until it is maxed and then start on another planet. not spread them around like they can/have to with this artifact, and if you don't like it simply don't do the mission.

If i have a max of 1151 energy and a ECR of 42 Ph, completely focus on this mission.
Do you guys think i could do it before it ends?
Keep in mind i level up once a day/ once a couple of days also, so id get the 1151 boost.

barely. you level very slowly. youll need to level at least once every two days in order to finish on the very last day. and you cannot afford to waste energy doing anything else. every energy point youd get would have to be reserved for the mission.

cause it costs 22500 energy to complete. but youll only get a little over 14100 without any level ups. so if you level up once every 2 days thatll give you a bonus 1100 energy per level so 7700 energy. 7700+14100 is 21900.

so you may need to level either one extra time or use an energy cube. but if you focus on it you can do it.