1.14 The End Phase
Q. In what order are things carried out in the end phase ?
A. Any special events which take place during the end phase, such as critical hits on a War Engine or an Eldar Avatar leaving the battlefield, are resolved before formations rally unless otherwise specified. If both players have effects for the beginning of the end phase, take turns resolving them, alternating between players for each subsequent effect until all effects are resolved. The player with the higher strategy rating has the option of actin first or forcing the opponent to act first.

Q. When exactly in the end phase does the additional damage from Plasma Reactor Hits or Gargant fires happen ?
Is it before or after rallying or repairing shields ?
A. Unless noted otherwise, things like this should happen at the start of the end phase, before you do anything else.

Does a Gargent get Blast markers from Fire? Or more Generaly, do additional damage from critical hits generate blast markers?

3.2.3
Q. If a Titan loses an additional point of DC due to the effect of a Critical Hit in the End Phase, will this place a BM and/or can this loss of DC inflict further critical damage ? Can this loss of DC be avoided by shields ?
A. Additional damage inflicts BM and can cause critical hits normally. Such damage may not be avoided by shields.