Am I missing something with the Chaos Guardian?

Playing through ATM9 tts right now. And the Chaos Guardian, while not impossible, seems like an incredibly annoying time sink? Tts has no Morgan (nothing from that mod), no iron spells, nothing that normally I would see recommended to help kill it. I've resorted to using a fully enchanted awakened supremium bow, but it took probably 200 hits just to get it to the 2nd phase. And that took close to 30 minutes, maybe my aim just sucks. But that's still doing more damage than my "fully maxed" wyvern bow, and to create any of the other bows from draconic evolution in atm9 tts it seems like you have to kill the chaos guardian atleast once. Also, no shield module, because again you need a dragon heart to craft even the most basic tier.

I have to be missing something right? What did y'all use to kill this thing for the first time in tts?

Ps: the gravity well phase is even worse. Just dig a hole and afk for 5 minutes while the withers just fly around I guess.