The more flexible a Tinker, the more likely it can find something powerful while also acting as a toolbox ([casthaven]Panglacial Wurm[/casthaven] is accordingly the least flexible Tinker around)
Ruling-wise, BREAK evolutions only simply append extra attacks to the existing Pokmon, so its theoretically possible for there to be a Pokmon-EX BREAK but thats really overdoing it
If 2 of them are heads, this attack does 50 more damage
The most cost efficient are the classic Relentless Assault, which sets a benchmark for how much these effects usually cost, and Fury of the Horde
For example, if you control The Ozolith when Essence Channeler dies, you'll put the appropriate number of each kind of counter onto both The Ozolith and the target creature
Steelix is a Stage 1 card so you would not necessarily have a stage advantage over your opponent, but heres how the combo worked: ![]( - This Steelix's attack did either 30 or 50 damage, both quite a lot considering the average HP of cards at that time