That could be one on the first turn, like Goblin Guide attacking on the second turn for a card then pre combat
The opposite is true for selling
This means that by simply casting additional Planeswalkers, Flux channeler's owner can increase the loyalty of each other Planeswalker they already have in play
They probably average about 5 mana
If another effect (or effects) modifies how much damage a source would deal to the chosen player or a permanent they control (for example, by preventing some of that damage), the player being dealt damage or the controller of the permanent being dealt damage chooses the order in which any such effects, including the effect of Sawhorn Nemesis, apply
Damage-based removal will only make Anti-Venom stronger, which can easily turn him into a game-ending threat