So i have just figured out the fastest and easiest 99 you can get heres a better RC guide!
Note- Having a summoning level of 96 for Pak Yak makes this easier!To start the adventure of 99 Rc go here in your spell book:


You should see a list of skills pop up choose Runecrafting:

Once there trade to Aurbury and buy one air talisman, one fire, and 23 Rune Essence:

Invetory should look like this:

Now here is where th Summoning helps! Go back to home and bank your items. Then take out a Pak Yak, summon it, and store 22 rune ess in it:

Now you should have your invetory looking like this with one rune ess and the air talisman. Then right click the talisman and press locate:

You will then be taken to the Air Rune ruins. Once there walk up to the big circle object in the middle and click it. You will make the runes and recieve 150k exp making you level 53:


You should then tele home and take out one firetalisman and 1 Rune ess and locate the Fire Rune ruins. Now that you are using the Pak Yak this is where u will gain XP like a boss! Once at the ruins only do one ess at a time. This will give you 600k exp per rune ess and magically you only make 11 runes everytime! Now you might be like why would i only do one! I can multiply my exp and be 99 in a second! Well it dosent work like that, you only get 600 exp per invetory of Rune ess thats why using one at a time is the best! After you click the ruin you will now be 70:


After this repeat only using one Rune ess at a time till level 99!
I hope this helped you get the fastest 99 in the game!-Ilovepoon