Platform: PC
Game Mode: Draft

I cast HULK SMASH!, choosing the mode where Captain Mar-Vell, Space-Born (4/4) dealt damage equal to its power to my opponent's Wakandan Drone Flock (3/3). The Drone Flock died as expected.

Later during the same turn, my opponent cast Red Guardian, Super-Soldier. Its triggered ability should have been able to target Captain Mar-Vell because she had dealt damage earlier that turn. However, Arena did not allow Captain Mar-Vell to be selected as a target.

Expected result: Captain Mar-Vell should have been a legal target for Red Guardian's triggered ability.
Actual result: Captain Mar-Vell could not be targeted.
Possible Explanation: It appears Red Guardian, Super-Soldier does not recognize damage dealt from Captain Mar-Vell via HULK SMASH!