Warhammer Mace

I have a question regarding blood tithe abilities Firstly I have tried searching but it kept bringing up skaventide discussions etc The 4th Ability apocolyptic frenzy it says pick a khorne unit within 3" of an enemy unit and pile in and attack with that unit So if I charge with something and attack with it can I immediately spend 4 blood tithe and pile in and attach again or is this stopped as I'm in base to base contact, Looked through the core rules on pile ins etc and nothing says you cant pile in if your in base to base just you have to end your move no further away than the closest enemy model Can someone help clarify?

are those dates purely AoS club nights or do you do AoS on other nights too?