How do you stop a team with a fed Tryndamere, Katharina, Kha'Zix, Caitlyn, and Annie? Split pushing and resets galore. Thankfully we were ahead in kills, but that didn't stop them from taking every tower except for our mid inhibitor tower. We got lucky and caught a few people out which led to a free Baron and eventually the win. We'd easily win a 5v5 team fight but never got it.
Edit: our team was Volibear, Olaf, Lux, Jinx, and Nami. Ended up getting a Bork because I needed the chasing power.
You build armor. Katarina's damage isn't that high without resets, and in that setup she's reliant on AD champions to get people low enough for her to reset off of them. This also presents the Kha'Zix resets and at least gives you something resembling a means of dealing with Caitlyn and Tryndamere.
Invade level one. Yeah, invading into Annie sucks, but Trynd, Kha, and Kat are all pretty trash level one, especially with a catch chain like Lux-Voli-Nami. Try to get both blue buffs. You want to put Kha behind
and get the timer on the buff. Remember that Kat isn't likely to take blue buff, so if you have the timer you have a good chance to harass him when he comes back for it. You don't actually have to do much more than this to slow Kha down enough for him to become a non-factor, since Jungle Kha just doesn't have the bankroll of Mid Kha.
You gank Tryndamere early and often, because once he reaches take-off velocity he's not coming back down. Lux vs. Katarina is going to suck unless the Kat is bad, and unless she's
really bad ganks aren't likely to help, but Lux should at least be able to cover the tower and stall the lane. The same for Jinx/Nami vs. Cait/Annie: accept the jungler's going to be living in the top lane and just concentrate on delaying the tower take for as long as possible. Resist the urge to fish for picks (they're probably gank-bait) and save Flamechompers/Bubbles for escaping.
The first dragon is probably theirs since their bot lane is going to be able to pressure yours, and their Lv6 is generally too risky to deal with unless you have superior position. Try to use the opportunity to gank Tryn again and push top lane back to the second tower. Get that lane nice and long so that you can actually punish him for pushing it later, just remember that if you get the Tier 2 tower he might freeze to farm, in which case you're going to need to send your top lane down the map to spread the love jungle's been giving him to everyone else - get some nice revenge for all that lane-bullying you've been suffering.
The minute Tryn starts playing at a split-push, group as five and rush down mid. Their wave clear is a combination of Caitlyn and prayers, and their siege defense isn't much better. Their only real option is to try to all-in you with Annie, Kha, and Kat, and if they do it with Tryn away you should still win as long as Jinx and Lux aren't out of position. They can't reset easily off Olaf and Voli.
Your teamfight is about staying out of the jungle unless you have absolute vision superiority and grouped as five. Annie and Kat combo might seem scary at first, but you have enough CC and survivability (heals, shields, and innate tankiness) to overcome it. The real danger is having stragglers get picked off and ending up with a running teamfight where Kha and Kat are leapfrogging all over people.
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