Got my reqs.
Tornadus-T - This thing is just devastating on any type of rain team. Easily rips apart teams that are not prepared for it and even those that are. Checks like Rotom-W are easily worn down before this thing can come in and 2HKO it with Hurricane. What makes this thing even more dangerous is its Speed that allows it to outspeed previous top speed tier Pokemon such as Latios and Alakazam. Regenerator is too easily abused on this thing, U-turning whenever it wants and not having to fear Stealth Rock
Keldeo - The pony is a huge threat to any teams that aren't prepared for it. However, it cannot not destroy teams as easily as Tornadus-T can. There are a number of solid checks to Keldeo such as Celebi, Jellicent, and Toxicroak. Most of the Keldeos I saw were the Choice Scarf variant which are great late game cleaners if the checks are appropriated. Ironically I believe its most dangerous set is the Sub+Calm Mind one but I did not see any of these while laddering.