So I've been wondering a while on the opening rotation, why do people insist on starting with bio 2? Seems to me its better to go like this single target:
Bio 1 -> Bio 2 -> Miasma (has lower time to be registered as up for fester than bio and bio 2, so you can fester faster) -> Fester -> Swiftcast Shadowflare -> Ruin -> Ruin -> Bio -> Fester -> Contagion
This way you'll get 2 full bio durations outside of the contagion boost, both with raging strikes up. In addition its generally better to start with your highest potency per tick dot as a rule of thumb. You get roughly 45-50 more potency out of your opening rotation like that.
Edit: Actually, I guess the argument is people don't want to delay contagion by waiting the first bio out, so I will take the time to do the maths of that opening's increased potency vs potency lost by holding contagion for a bit!
So the delayed contagion will be without raging strikes, since you'll be able to get raging strikes off and have contagion back in time to extend those buffs on the third one. I will also assume that this is a scenario where you can maintain dots even without contagion, though that does admittedly make it slightly off topic for a thread on kiting renauds as SMN, though it is relevant to t6!
In this case, the bonus damage from a contagion adds nothing to your 3 main dots, as you'd refresh those manually anyway, and as such the bonus potency is nearly completely gained from extra Ruin casts from the saved GCDs, so lets figure out just how many ruins we can cast as a bonus from one contagion.
Contagion obviously extends the dot timers by 15 seconds per dot, so we can say that the extra time to cast ruins gained is equivalent to how much of the dot 15 seconds amounts to. If I am speaking a bit weirdly, it is because I am not a native speaker, so apologies. For an example: Bio 2 has a 30 second duration, so contagion's 15 second boost amounts to 50% of the total duration of a bio 2, and as such nets you an extra 0.5 GCDs worth of ruin, or 40 potency. By this logic we can quickly figure out what the saved GCDs of each dot is.
15 seconds is:
83.33% of Bio 1 (18 total)
62.5% of Miasma (24 total)
50% of Bio 2 (30 total)
Thus a contagion without any buffs nets us a grand total of 1.958 GCDs, but for simplicity's sake, lets round that up to 2, making an unbuffed contagion a grand total of 160 bonus potency above your regular rotation, before adding in miasma 2.
Miasma 2 is obviously a different beast entirely, as it wouldn't be used without contagion due to only having a base total potency of 70. Adding another 15 seconds, or 5 ticks, makes that 120, or a bonus potency of 40, since you have to detract the potency of the ruin you are choosing not to cast by casting miasma 2. This means contagion without raging strikes has a total bonus potency of 200.
Now if that was the end of it, obviously 200 is a whole lore more than 50, but we have to bear in mind that we are not delaying contagion for nearly a full duration, so next we will figure out exactly how much we delay contagion by using this different opening. For the purposes of making this simple to read, and bearing in mind how summoner itemisation goes in the first place, we will assume we have 0 spell speed on gear (sure would be wonderful if that was true, eh?).
Note that I have intentionally removed fester from both of these, as both rotations time them when using instant casts, so they have no bearing on these calculations.
The original rotation goes: Bio 2 -> Miasma -> Bio -> Swiftcast Shadowflare -> Contagion
Meaning contagion occurs roughly 7.5 seconds into your rotation.
The rotation I mentioned goes: Bio 1 -> Bio 2 -> Miasma -> Swiftcast Shadowflare -> Ruin -> Ruin -> Bio -> Contagion
Meaning contagion occurs roughly 17.5 seconds into the fight, so we're delaying contagion by roughly 10 seconds.
Contagion has a 60 seconds cooldown, so this means we're delaying contagion by 16.66% of a cast. 16.66% of 200 being 33. So our delay of contagion makes us drop up to 33 potency, in favor of gaining 50, for a bonus of ~17. Its not a big difference, but I like to min/max and it just struck me as odd. Also sorry for the long rant in an attempt to argue against my own point, heh.
TLDR: Rotation I suggested has very slightly higher potency.
In an attempt to drag myself back on the t7 topic, do you know if your group wants you to do the stacking method for Renauds (get 4 in position for healers to freeze all at once and then just be done kiting) or keep them up one at a time? Both have pros and cons, but tips and help we can give is depending on which you're doing.