You have this as LL, but Wrath has it as DD. One of you must do better than you think.
If Wrath suspends his threat first, Sea's Claim + Unsummon locks him out.
If Wrath Duresses Unsummon, Sea's Claim locks him out.
Wrath must Duress Sea's Claim first. Then you both suspend your threats. Corpse is a turn slower (suspend 5) but evasive. Is
Unsummon on Corpse enough tempo for you to win? It's enough to stop Wrath from racing, but Disfigure prevents 2 damage to slow you down a turn, and when Corpse returns on defense it can force a draw. This needs some math.
Alpha vs Wrath OTP
A - Suspend Deepwalker, 4 counters
W - Duress Sea's Claim
A - 3 counters
W - Suspend Corpse, 5 counters
A - 2 counters
W - 4 counters
A - 1 counter
W - 3 counters
A - Deepwalker attacks for 3. [W=17]
W - 2 counters
A - Attack [W=14]
W - 1 counter
A - Attack [W=11]
W - Corpse stays back to block.
A - Unsummon. Attack for 2 (blue is tapped). [W=9]
W - Suspend Corpse, 5 counters
Deepwalker wins in less than 5 attacks even with
Disfigure preventing 2.
Between going first, forcing Wrath to cast Duress before suspending his threat, having shorter suspend, and Unsummon, you buy enough tempo to get enough unblocked attacks.
Alpha vs Wrath OTD
W - Duress Sea's Claim
A - Suspend Deepwalker, 4 counters
W - Suspend Corpse, 5 counters
A - 3 counters
W - 4 counters
A - 2 counters
W - 3 counters
A - 1 counter
W - 2 counters
A - Deepwalker attacks for 3. [W=17]
W - 1 counter
A - Attack [W=14]
W - Corpse stays back to block.
A - Unsummon. Attack for 2 (blue is tapped). [W=12]
W - Suspend Corpse, 5 counters
A - Attack for 3 [W=9]
W - 4 counters
A - Attack for 3 [W=6]
W - 3 counters
A - Attack for 3 [W=3]
W - 2 counters
A - Get Disfigured and attack for 1 [W=2]
W - 1 counter
A - Attack for 3 [W=-1]
You're still just barely fast enough to kill before Corpse comes back.
Wrath should draw the other matches, but
Unsummon seals this one for you.