Secondary Reccomendations for a DB or Ninja Blade user

So I’m interested in those two powersets for Stalkers specifically, but I have no idea on what secondary to choose. Originally I thought about trying out Radiation or Armor or just going with Willpower but, from what I’ve heard, Defense sets are preferred for stalkers. So my choices now are around Super Reflexes, Invulnerability. Energy Aura and Electric Armor seems interesting too.

Anyone with experience with any of these?

I’m enjoying Ninjitsu. Good defenses, utility and a heal.