For Gamma use a army of r-gigas or R-reapers (just cause R variants have boosted stats)

For Beta tame the 3 titans and fight it along with any left over creatures from the gamma fight

For Alpha use any left over creatures from the previous two fights (including titans) and a mega-mek using the module obtained from the beta fight (I would suggest combining ascendant meks for the mega-mek so that it's stronger) hope this helped

To defeat. From the information I’ve gathered, cover the edges of a desert titan plat saddle with tek (cluster) or heavy (normal) turrets. Have multiple high level carnivores to distract minions, bring a few velonosaurs on the desert titan, make sure they have high stamina, bring both other Titans, farm for a max level mech, and get enough to make a max level mega mech for each player going to the fight. It’s always good to bring a backup mega mech in case the one your using dies. Bring a good assault rifle and 1000 - 2500 ammo. Bring a daedon with high food stat on the desert titan for passive healing velonosaurs and the titan, bring around 50k raw meat for the daedon, starve it before heading into battle, if you beat it with my tips, then you just got tips from someone who hasn’t even gotten an artifact yet, and killed one of the hardest bosses in the game with them.

The alpha can be done fairly easily with the forest titan's high health to tank hits, the ice titan for high damage, and the desert titan to deal bits of damage here and there. All you need to do if solo is get in the mega mek whilst behind it and spam attacks, if you've got a tribe get others in really good mess and spam shots with the pistol

Think of the king Titan as all of the bosses rolled into one. I have 2 friends that helped me with this fight, you do not need army’s of gigas, we breed up a bunch of managarmrs and the three other Titans, and we each brought in a backup enforcer and blueprinted mek’s each of us with a different attachment, we had full blueprint tek gear and sword along with blueprint Railguns, med brews, and 30k hp brontos with tek turrets and side armor built down to cover its body. We whistled the manas to attack and set the bronto to neutral, and powered up its tek turrets. We all went around on our mek’s beating the corruption he summons. We would periodically send some rockets into him, and the Manas were jumping everywhere, we also had a yuti, he was dead in under 25 minutes. This was beta fight. Ice breath shreds stuff like nobody’s business. We had to turn off rpg damage numbers, it lagged too much.