Undergeared Assault Tiamat Solo
Basically, showing that it's possible even without being overpowered, but it takes a while though lol, my fastest time is 16 mins, but in this video it's 18.
Semi-F2P player, I bought the Ace Founder Pack, and that's about it. All my costumes/2* accessories are untuned. +11 weapon at around 12-13k raw, 330% critical power, 85% critical rate, 60% defense penetration, no damage consumables (I regret buying Slot B for this, the 1 second lag is annoying for controller users), no cash potions (in this video I used the HP one like 3 times I think, but that was just me being greedy with dps) and full talismans. Pet is Mini-owl just to give me 300 raw buff, doesn't really help that much.
My point is, don't give up if you think you can't do raids like this just because you're not a P2W player, you can easily beat this and any future content without paying a cent, just practice now and then.