The points you need for the system will be available in the arena shop for 450 per 40 points so save up on arena pts now. Also in the same week they introduce the system there should be a "summon scroll" available for both p2w/f2p in the events that gives you the ability to use one of the following summons as your companion genjutsu crow, purple monkey or purple slug. The cult runes are also available for purchase from regular shop but it costs 10 cps for only 10 points so its not worth at all

books in treasure? can you be more specific or just post a screenshot

There is no such update coming but you should continue collecting summon scrolls and wait for a rebate.