Hearthpwn

i dont see major mistakes in your gameplay.

mulligans are fine

game 1 choosing annoy-o over pompeus turn 3 is a slower approach to the game. and as arena is mostly tempo based i would have taken a different route. also cult master over piloted shredder is debatable tempo wise. your turn 8 was too slow aswell, i would have preferred going for the firelands to get some pressure off his side of the board instead of taunting up giving your opponent the trade-initiative. you effectively traded 2 taunts and a whole turn for 1 minion and a weapon swing. think you could have taken the risk of tanking dmg to the face especially with kraken the next turn to remove a minion

if at all, you are a little bit too risk averse especially in the 2nd game not using firelands portal earlier. i think the 2-roll on the implosion instead of firelands might have cost you the game. also big bad archmage was played too late imo.

game 3 turn 13 shoulda ping + trade first and then bomber probably. the deadly shot kraken was unlucky, it was still the right play though

all in all you are playing a more value-oriented game choosing "safer" options thus giving your opponent time to recover instead of taking an aggressive turn to seize initiative an pressuring your opponent. id say: play more aggressive to set your opponents on a clock and make them spend their ressources in an inefficient manner.

just my 0.02$