Talk:Upgrade/@comment-213.149.57.71-20170314092257/@comment-25435121-20170314232841

The max gems you can get at each castle level is already listed on the Buildings page.

To get to max level (90 for an LR) would take:
 * 50,858 level 300 FAW battles with no EXP boosters
 * 38,144 level 400 FAW battles with no EXP boosters

If you use 2 GSR Fortuna, those numbers go down to 36,328 and 27,245 battles respectively. If you play moderately often killing 200-300 FAW per event, you are looking at about 100-200 events for max an LR to level 90. It may as well be impossible.