To clarify, Second Coin Toss doesn't allow its user to redo the flip for Lucky Chance, so it's best to choose the optimal flip for that card the first time around
If its your main phase, there is an additional combat phase after this phase
Within each color, you can take it further by sorting cards alphabetically or by mana cost
Klothys definitely has the potential to push the Gruul Aggro archetype further than it has been during this Standard season because of her cheap mana cost, dealing two damage per turn and shes relatively easy to turn into a creature because of her ability to ramp
My favorite is Torrential Gearhulk, which is a strong win condition for control decks, allowing you to ambush your opponents creature with a 5/6 flash creature and cast a strong instant from your graveyard like Cryptic Command or Magma Opus
Bruise Tarl will give target creature you control double strike and lifelink until end of turn when he enters the battlefield or attacks