Dark Wood Grain Ring
With this ring you can basically decide when you want to be hit and when not, because of the crazy i-frames. Counter hits are way more difficult to land and after kick hits fail.
If using DEX or STR weapons with it you don't really need to sacrifice that many stats from endurance or vitality since you only need to invest 28/40 points for them, it is always worth the lost hp or endurance, because you are very, very difficult to even hit.
This ring makes roll bs walk in the park.
Pyromancy
Well....it's free. Only thing you need to invest is few points in attunement to get all the most powerful pyro-castings to your backpocket. Even on the high fire resistance setup it strikes ridicilous dmg, expecially great combustion and black flame are so badly unbalanced that there is no other in this game. Expecially DEX-builds benefit greatly from pyro because of the speed buff.
Crown of dusk
Makes any casting do ridicilous dmg.
Dark Bead and Pursuers
Have potential to one shot players with no effort at all and benefit greatly from lag/latency.
Katanas
Just the most optimal weapons in the game. Only need investment in DEX, have good dmg (expecially Chaos Blade), bleed (expecially Chaos Blade), crazy good moveset and decent range (expecially on Chaos Blade and Washing pole).
Blader Side Sword
This thing has insane range and speed + is a total pain in the *** with Leo ring + it overshadows all other straightswords since it has most of the scaling on only DEX.
Buffs
Dark Moon Blade and Sunlight Blade just add way too much dmg that's all there is.
Family Masks
After the recent patch these are not so much of a problem, but still the most optimal armor choice for head gear after the Crown of Dusk and Crown of the Dark Sun. Just a patch of shame really.
Spears
Do I really even have to say? Unbeatable when using the poke flip poke flip technique.
These were my best explanations why some things are considered tryhard.
I don't really care what things people use in the tournament, bring what ever you want and use what ever you want, but I really hope people still have some imagination.