Isshin, Two Heavens as One's ability affects only triggered abilities with conditions that are directly related to attacking, such as "whenever [this creature] attacks" or "whenever you attack with one or more creatures." It does not affect triggered abilities with other trigger conditions, such as "whenever [this creature] becomes tapped." Isshin's effect doesn't copy the triggered ability
One land, one planeswalker, two enchantments, and six creatures sums it up
He can also reliably pitch your hand into your graveyard, which can make a good setup for graveyard strategies - whether you're trying to get an Underworld Breach / Lion's Eye Diamond loop going for a combo, or just want to reanimate something huge
Death Toll Death Toll is a bit of a strange deck
Planeswalkers are also a strong choice against tapping strategies
Whats best about Tivit is the additional vote it gives you whenever a card calls for a vote