Rockantium

Rockantium was the first earth-type monster. He is slow, but can be very dangerous by the way.

Overview
Unlike other terrible monsters like Nebotus and Thundhare, this monster isn't that bad, but jesus, he is sooooo SLOW, he will be outsped from every monster you may encounter, even thought he has no stun or Hardened trait, he will have lots of stuns, freezes, and possesses so basically it be easy to foes to kill him easier before he'll use any attack and suddenly will be killed, but still, he is not bad monster, since he has alright Attack stat, he may at least can OHKO one foe. But seriously, thought he will be not necessary in a future, just give him Gold runes instead.

Positives Negatives
 * Decent Skills.
 * Not many cooldowns.
 * Horrifyingly slow.
 * Bad trait.

Skillset
He have no choice but simply get outspeed and simply die, but to make him at least survive and go for Protect all Team, then the Life runes will be your choice but since he'll get stunned, frozen, or possessed, 3 Speed will at least he will have a chance, since he is a stun debuffer, he can outspeed and at least stun one Dark monster that doesn't possess the Speed runes and attack other monster further, and if you have WAYYY better supporting monsters example General Thetys or Nishant's Pet, go for Team Speed, this way this gives them to at least outspeed the other monster that has higher Speed and give debuffs while a other better Attacker can outspeed and OHKO all foes and him can at least do same thing, or simply go for Team Strength if you have problem with Attackers and want them to stronger and OHKO things and especially for him.
 * Rock Avalance
 * Stone Rod
 * Rockorites
 * Protect all Team
 * 3 Life Runes / 3 Speed / 3 Team Strength / 3 Team Speed

Counters
Since he has horrible Speed stat, he can be outsped by any Dark monster and eat him for dinner, regardless if they use Strength runes, you can simply stun, freeze, or possess him to stun his foes, and end things all.