Who / What / Where / When / Why 5W is like a lot of flexible cards in that it isnt really efficient at doing anything specifically because each mode costs one more mana than the general cost (1R is the general cost of a Shatter effect, but on What it costs 2R) aside from the Stream of Life mode on Who, which is pretty suboptimal
Depending on your personality and play style, this sort of chaos can be either very fun or very frustrating
Replacements Draconautics Engineer is nowhere as good as Voldaran Thrillseeker for Vivi, as it lacks the direct clean finish punch that Thrillseeker gave, and the additional counter synergy it functioned with, but the Engineers pair of abilities will work with him under Agathas Cauldron to let team Vivi make a bunch of dragons and haste them
One token doubler, anthem, or Impact Tremors effect sends the damage spiraling out of control
Ishai, Ojutai Dragonspeaker [Partner]: That's a lot of counters if you have many opponents