Ok this is just a few tips for the guys that are stuck on beating
Ragnarok

1. BE PROMETHEOUS He's the heaviest heavy mech u have at this
point.

2. KEEP YOUR DISTANCE that lava gun kills almost half your energy
at close range so try to stay far away and launch long range
attacks.

3. BE SURE YOU GOT UPGRADES its almost impossible to beat him with
no upgrades.

4. TIME ALL OF YOUR ATTACKS That shield gets really frustrating
when it absorbs your last upgraded attack, so time your attacks
carefully.

5. USE THE FIELD AGAINST HIM There are some buildings like mining
wells that give off a blast when you knock them down. If you can
get Ragnarok next to one when it blows he'll practically die.

6. IF YOU DIE JUST KEEP TRYING I got killed a bunch of times
battling him, just keep trying.