User blog comment:RoznosicielCiast/Is Darius being secretly nerfed?/@comment-5556439-20130824013219

Darius is really well balanced but I presonally believe his passive (at max rank) 25% Pen is a bit much.

Champions with easily abusable mechanics like Darius' passive(At top lane) and AS slow are always closely watched by Riot. Other abusable mechanics like tying AoE and disengage together, and  are examples. They can deal damage outside of melee range and easily leave the window of counterplay that they just created due to mobility or disengage.

Riot always keeps close watch on these kind of things and for good reason. Darius has really easy laning and can be a bit braindead if your not against a good opponent. To the point where Darius himself can get boring.