Being LFR, you could be spamming atonement only and still come out perfectly fine, but lets imagine these as normal/hc bosses.
Blade Lord: your spirit shell is very low. You can spirit shell almost every unseen strike (it starts getting slightly delayed if you need to move from a tornado or smt and cast shell 2-3 seconds too late. Not only it gives amazing numbers, but in a normal/hc situation, spirit shell can save some insta-gibs from unseen strike. So, what you do for this boss is: shield the tank before pull>penance the boss while moving to position (if you have it glyphed) under the effects of borrowed time that you just got from the shield> holy fire (also can be done while still moving if glyphed) > 3x smite. When you see the unseen strike counter @15 seconds left, pop archangel/spirit shell/power infusion and cover the raid in shells, which will mitigate A LOT of dmg (in 10 man, prolly most of it, and power infusion might not be needed since you will cap spirit shell anyway). After unseen strike, re-charge the 5xevangelism, while not forgetting to shield the tank for rapture. If there is another disc, try shielding the wind debuff ppl (you should have them marked on your frames, and its good to keep an eye on them to toss a shield in case they dip). Repeat the whole spirit shell thing as close to 15 seconds before the next strike as you can. For the gauntlet phase if you can spare the attention, give ppl around you few shields, if you're specced into body&soul it will help them with moving and give them an hp buffer. Once back at the boss, you can prayer of healing your raid if ppl were slow and got low, or you can just smite if the raid is stable. Depending on how stable your tank looks over the fight you can use Inner Focus for a gheal on him when he dips low or you can use it with spirit shell for fatter shields (in 10 man, it will prolly cap it so no real need to use it like that).
Garalon: technically if you can stand in the legs and dps them with 50% more dmg, atonement can be really good, especially in a 10 man environment. Spirit shelling before the crushes is nice (its a bit harder to predict when they will happen outside a very organized raid, so you can just use it on cd if knowing when your kiters switch is complicated). It's also very good against high stacks of pheromones.