Earthshaking Strike is quite an eyesore, Pommel Strike is better just by considering that. But honestly I would go with To the Death.
Earthshaking can be a literal eyesore because the flame effect is really bright white, and it is bad DPS on initial hit and from the flames.
Mighty blow and charging bull should always be used, and imo, high crit and flow of battle should be bee-lined for. Quick summary of my opinion of other options for active abilities:
To the Death: Quite good ability. Yell at an enemy, run him over with charging bull or hit with good DPS ability, get full guard. Can use on venatori and red templar commanders, but vs. the RTC, make sure to kite around to keep yourself safe and tell teammates to kill the RTC while you run around screaming. Can also yell at a high hp enemy you think won't be killed, focus on other enemies, then go back to the yelled-at enemy when you want more guard.
Combat roll: Decent for boosting survival if you use it right after having a CC applied on yourself and to avoid big hits. Definitely makes demon commander easier. Can be very bad if you are playing off-host and have less than optimal ping.
Whirlwind: Decent damage and guard generation IF you can survive swinging at enemies for a while and your team allows enemies to be grouped up around you (static cage, PotA, all your friends dying). Can be pretty good damage if your teammates prime a lot of combos because each swing of whirlwind can detonate them. CAN BE BLOCKED and then the ability will end, best to use after the enemies that can block have been CC'ed or don't have their shields aimed at you.
War Horn: Can be good CC. Be careful about ranged enemies running far away and then killing you and your team from even better positions than before. Rather long ~2s animation before fear applies.
Pommel Strike: Decent single-target DPS and stun. It is easy to miss enemies with it however, especially if they are short or in weird positions.