u/Apollo9975

Is the following the correct interpretation?

Player A activates Titaniklad during the End Phase, as Chain Link 1. They do not have to choose whether to Special Summon or Add at this point, nor do they have to choose a card yet.

Player B can choose to activate Mulcharmy Fuwalos in response.

Player A now picks the card and can decide to add instead of summon from the deck.