I just had a family emergency come up (everything is mostly fine) and I have to travel suddenly. Please accept my apologies but I couldn't plan for this king of thing. Carry on brothers, and for anyone that plays Vetari: My warcaster feat allows Vetari to cast spells as an attack of opportunity as long as the spell casting time is 1 action. Additionally, I can cast 'through' my familiar, which means if a creature leaves my threat range OR my familiar I can use my reaction to cast a spell as an OA.. Good luck!
