I like this deal for you. Although I prefer Tarasenko to Etem they are actually pretty close IMO. So the deal becomes Seguin+4th for your Bernier+1st+2nd. I do that deal all day long. I put in Bernier as I'd prefer you to keep Markstrom but I would still do the deal if you had to give him up instead.
10-team Auction League, $160 team salary, weekly H2H, start: 6F, 4D, 1G and 5 Bench
Scoring structure: (F : 1pt G / 1pt A / 0.15pts SOG / 0.15pts Hits / 0.15pts BlkS), (G : 5 pts W / 3 pts SO / 0.01 pts Saves)
Forwards : Ovechkin ($41), Kovalchuk ($24), Kessel ($18), E. Kane ($13), Benn ($5), Sharp ($11), Pominville ($1), Dupuis ($2), Whitney ($2)
Defenses : Letang ($24), Byfuglien ($6), Markov ($1), Bogosian ($1), McDonagh ($2)
Goalies : Schneider ($7), Bobrovsky ($1)