This is just an edit of https://dundefplanner.com/map.php?load=1238 by Traxar. That build wasn't working for me likely due to low stats so I decided to make use of some minions.
His build is for sure faster if you have the stats for it.
(1) the fireball towers are located further back so they can overlap with the crystal to ensure wyverns don't kill the crystal.
(2) I put two guardian summs and 1 dps summ on this stack.
(3) Spiders up on the ledge to make sure stray ogre shots can't cause tower deaths.