With 'Chapter 1: Truce', the main source of Prismaticite Crystal was the Daily Dragon Responder which provided 6 Crystals for completing 3 DRMs. You could get another 3 for a total of 9 if you had Boon of the Deep Flame in all three missions (not accounting for rng drops from CMs).
Thus, if doing 3 DRMs daily with the boon, Dragon Slayer weapon collection would take 54 days to complete.
Azure and Crimson Dragon Slayer weapons each require 5 Prismatium Ingots, which means it would take 177 days to complete both collections if getting 9 Prismaticite Crystals daily.
The Daily Dragon Responder achievement however, was not expanded to account for the increased number of DRMs with 'Chapter 2: Power', it still asks to complete three and only provides 6 Crystals. The achievement should receive another 4 tiers of rewards to account for 4 new DRMs for a total of 28 Crystals daily, and then again when the last 3 DRMs are released for a total of 55 Crystals daily (reward scaling based on current system, i.e. if 1/3 missions completed rewards 3 Crystals 1/7 missions completed should provide 7 Crystal and 1/10 - 10 Crystals).
I will gladly do all 10 of the missions daily if it means I'm actually able to complete the collections much faster than in 230 days, without spending ungodly amounts of gold (around 1400g total at current prices for Prismatium Ingots for both Azure and Crimson sets, especially that crafting the Ingots already requires a significant investment in form of Orichalcum and Ectoplasm).