User blog comment:Legionaire22/Primarch Feats of Strength/@comment-4966170-20130702114037

Also:

Lorgar killed an Avatar of the Eldar War God and has after his ascention locked himself and meditates

Sanguinius killed a Keeper of Secrets and Bloodthirster

Curze could look into the future

Guilliman maybe killed a primarch

Fulgrim broke free of a greater daemon`s possion and mortaly wounded yet another primarch

It took several hundred Grey knights to banish Angron

Mortarion survived extrem toxic hazards and killed a Grey Knights Chapter Master, then got Draigo`s name carved in his heart

Perturabo constructed the Eternal Fortress, which nearly broke the Imperia Fists if not for the Ultramarines