What speed are Legend abilities (like Victor and Yasou) and when can they be activated?

Ruling: Legend abilities that don't say "Action" or "Reaction" are Base speed (also called "None" speed). They can only be activated on your turn in a neutral (non-showdown) and open (no chain) state.

Nuances:

• Base speed Legend abilities cannot be used on opponent's turns
• Base speed Legend abilities cannot be used during showdowns or in reaction windows
• This is equivalent to sorcery speed in Magic: The Gathering