Let create a new module to lower the cost in energy to make attack on a base
it cost badge to get it and it drop to 4 energy to attack legion base

-1 i think its fine as is.

Each attack against a base base gives a 5% chance chance to drop either of 2 artifacts

1.lowers energy cost to 4 for 30 minutes
2.lowers energy cost to 3 for 20 minutes

Only 1 type can be used at the same time
Can activate as many of the same type as you wish to extend the time limit
Can be removed using CM
Cannot be set whilst legion has a lock on an enemy base
Artifacts expire when base is disabled

So more or less every 20 hits. People can hit bases up to thousands of times, do you know how many activations of this that is, how much extra energy they'll have to spend, how much harder it'll make it to defend a base. A huge -1 from me.

-1
It is good as is. 5 energy is not that much