With Isshin out in play, if a creature attacks and causes a trigger of a card you control to go off, that trigger happens an extra time
In a format where everything was speed, speed, speed, Capsize single-handedly allowed blue to stay in the game, and eventually lock it up by returning two lands a turn to a hapless opponent's hand
That said, the deck felt like it had game in a lot of different matchups
If it's an enchantment creature or legendary creature, instead put a +1/+1 counter on it and it gets +1/+1 until end of turn
Id expect the various control decks of Modern to have some number of copies in the 75 moving forward
If it's a Siege, it will still be exiled when the last defense counter is removed from it, and its controller may still cast it transformed without paying its mana cost