Very helpful in raids as it can tank hits a ton if not affected by charge especially against turrets. Has resistance to any type of damage unless affected by charge. The king is best to be used in raids after you have broken past the walls. King can be weak to rock drakes as they get a buff near nameless. The king can be godly with daeodons and if all sources of charge is eliminated. Tail attack is good for damage and crowd control. Acid is good for damage over time and slowness on enemies. Bite seems to be worthless. Tail spins knockback is good to send people flying into the pits of radiation or other hazards.
It is the second strongest Reaper ingame. Only thing being better is the Alpha Surface Reaper. Getting impregnated by a queen lvl 150 and getting all 75 lvls possible for it gives you anreaper baby born with 15-20k HP which after imprint almost 30k. Dmg gets over 300% and after imprint close to 400%. Lvled can be 40k HP and over 600% if not 700% easily. Its a beast, can charge jump like a crab, take it down there to the drake nests and you can farm eggs for days. But be aware that light makes him weaker aka he takes more dmg and deals less.