I just feel like there needs to be a little some thing extra nothing major but something to add a bit more strategy and keep things from getting stale.

So I'd like to propose a system that let's players earn a kind of fragment(s) inside of any crate the player obtains, they have  to collect a certain amount of them and then pay arena credits to create a full fragment, which we will call a core.

So say it takes 30 fragments to craft the 3 most basic cores which are the following

1) - impact core - increases damage by 3%

2) - sturdy core - increase health by 5%

3) - heavy core - reduce damage taken by 6%

Then say the cores could come in tiers
So tear 2 could be something like 50 fragments to craft a core and they are

1) - swift core - increase speed by 5km/h

2) - reflex core - reduce reload speed by 3 seconds.

Then tier 3 could look something like this
70 fragments to craft

1) - aggression core - combine reflex with impact core

2) - solid core - combine sturdy with heavy core

3) - renewal core - heal 2% per second when not being attacked similar to mech M.D except no allies will heal from this.

Finally tier 4
100 fragments to craft a core

1) - barrier core - a full body shield activates once every 20 seconds after being depleted equivalent to 15% of the mechs health

2) - lag core - when a enemy comes within 20 meters of you they are slowly placed under the stasis effect

3) - overheat core - when a enemy comes within 20 meters of you they are slowly placed under the over heat effect

4) - proto core - ???????????????

Once a player has paid to craft the core it should cost the play a additional amount of A-coins to then permanently combine it to the desired mech.

Just a idea, a little food for thought.