The Mag-Pulse-Warheads card ability reads:
How does this work in conjunction with Fifth Brother's brothers ability to add 1 Critical Hit damage after the attack hits?
option a) The Mag-Pulse card text ist executed as a whole and non-divisible, therefore 1 Critical Hit damage from the warhead is applied and then all Hit / Critical Hit results are cancelled (including the 1 Critical Hit damage added by Fifth Brother's ability) => 1 Critical damage + jam + deplete
OR
option b) The 1 Critical Hit damage added by Fifth Brother's ability is added to the 1 Critical Hit damage from the warhead and immediately applied. Then cancel all Hit / Critical Hit results (but there are none left to cancel) => 2 Critial damage + jam + deplete
Thanks for clarification!
This question is very similar to the "Fifth Brother w/ Homing Missiles" topic