Key card and key card battles

Kevon

What are these platforms like? I was wondering if I need to rush (spend gems) to unlock these or just take my time and have them unlock as I progress. Is there anything special like rare shards? Thanks in advance for any responses.

Abyss

They are garbage with even worse rewards and a severe waste of energy

Just do each once for the achievment and move on

KTroy24

Not worth it bro, take your time. The best to rush to is level 40 for galactic war

Tomek

I have never visited key card battles - I always have better needs for 50 energy .
Is the only mats possible to win the credit and training droids ? The first I do not need , the second can be usefull but not very important.