Content should be challenging to execute... Not challenging to learn

[Chihaya]

Alexander got cleared within 2hr after it came out... you say they followed a guide? There wasn't one.
Did watching video or reading a guide to memorize things give you a free pass to clear t9 or t13? Probably not, you had to actually experience them, survive them and healers to heal through the high damage while dealing with such mechanics.

Remove the mechanics add in a DPS check - that's Bismark Ex that you are so fond of. Dodging a few telegraphs and hitting dragonkillers when the game tells you to - yea... challenge...