I've only been playing for around one month so my line-ups are not that great.
No, even the 2BP alone cannot get everything. If you can't clear 2BP I think you've really just gotta hope to get a good friend unit carrying you, because 2BP gets you slightly better than 1.5 times efficiency, and 3 BP is then worth four times that
Actually, imo. Depending on what servants and level, if you have a support with Scathach you should be able to do 300-500K minimum if you buff Scathach with her abilities, and if she has the 200% CE.
Also, a good start to getting the 200% CE from the shop is to get servants with a evade ability, and when you get to the 2nd wave, get the hands to a very low HP, and when you have about 3 turns left, take the hands out and you should be able to get enough materials to purchase the CE. That's how I got the CE pretty quick.
Thanks for the advice! I've been using my friend scathach and brynhildr and went full support mode with my mash,georgios and hans. Now it's around 50/50 when i tried the 2BP raid. Better than nothing i guess.
