In my experience, most people use either the present: "Ezekiel Tarus snaps to attention and offers his officer a flawless salute, barking 'YES SIR'!" or else a conditional like "Ezekiel Tarus would snap to attention ...".
A few people here referred to that as being the past tense, but, while I'm not a linguist so I could be very wrong here, I don't think that's what people usually mean by the past tense, like "I went" or "I have gone". There is like a future-in-the-past construction using would, e.g. "He was elected president, and would go on to serve for 4 years before retiring". But that's not really the same thing as "Mike would swing his sword". The latter IMO reads more like the conditional, e.g. "I would go to the shop if it weren't raining so heavily".
Actual past tense emotes like "Bob nodded, eyes shifting to the ground in shame" sound fine to me, but an overuse of 'would' where it's not justified sounds horrible. It has places where it absolutely should be used, like when your action is actually conditional -- "Thomas raises/raised his shield to block the strike, and if successful, would lunge for the assailant's chest with his free arm" -- in this case, Thomas won't actually stab the other guy unless a certain condition is met (i.e. he blocks the attack), so 'would' is justified and even necessary here. But "Thomas would raise his shield" is just silly because... well, did he or didn't he? If he did in fact raise his shield, why are you describing it like it's dependent on something else?
IMO the root cause here is that people don't want to be accused of powergaming. As new roleplayers, they probably got burnt writing emotes like "Jeff stabs/stabbed Tom" and so they started adding 'would' to everything as the easiest way to avoid getting yelled at. But IMO it just takes a contemplation of what you're actually describing. "Jeff stabs/stabbed Tom" is powergaming because it forces an action on Tom. You've given him no chance to dodge. But "Jeff lunges/lunged at Tom with his blade" is not powergaming, because a lunge is just a lunge and Tom can still block, dodge, etc.