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
Alright, since most of these tips are basically useless since most of them is complaining about Fortnite, talking about Pacific Rim, Godzilla, forcetame, marrying it, killing it with a pike and a dodo, and not actually going to make a real tip. (sorry if I am being triggered) What I did was get a max levelled mech blueprint and some auto turrets on a desert Titan of your choice. If you have a friend with you, you either let the friend pilot the desert Titan or control the mega mech. If you are solo, breed about 40 of Level 500 T-Rex (not 500 lvl 40 rexes or else it will be time consuming as well as not able to survive as long especially if it’s Alpha) to distract the corrupted creatures that it spawns and make sure you pop ascendant saddles on them for extra armour. Set the desert Titan on neutral since if it the king titans or the other ones gets close it can protect itself. If you are doing CrossArk, have some wyverns to assist the Titan set them on neutral too and put reapers.🙂
Will people please make real tips? Generally giga rushing is a valid method, as it is a open world boss. In addition, a high level Mek with a shield or pod module can prove to be very helpful. Titans will also aid in the battle due to their high health and damage.