Who am I?
Well, this is a good question, actually I am nobody, I am not a really good player, only Plat. BUT, I do main Rek'Sai and know pretty everything I need to know about that champ.
I know there are pleny of guides about Rek, but none with trinity and that's pretty much the base of this one.

Pros

+ AWESOME LANER + STRONG SUSTAIN + NO MANA + BRING CONTROL ON TOP OF THE MAP

Cons

+ CAN'T SEE **** WHEN BURROWED + AWFULL LANING AGAINST AP CHAMPIONS + ONLY ONE SPELL THAT REALLY DO DMG + POSITIVE ATTRIBUTE[/columns}

Masteries can vary, depend on what you have against you and also with you. 2 options : OFF-TANK or TANK-TANK-TANK.

OFF-TANK

K I L L

sp

T H E M A L L

// OFF-TANK - 12 OFFENSE / 18 DEFENSE / 0 UTILITY // Those are the regular masteries, you play as the bruiser on toplane.

TANK-TANK-TANK

S O M E

sp

T A N K Y N E S S

// TANK-TANK-TANK - 6 OFFENSE / 6 DEFENSE / 18 UTILITY // Pick those masteries when your team doesn't have any tank, you won't be the best tank but damn, you'll do your job!

• Seal of Armor: Every champ needs armor, this one bring some early armor to resist even the first auto attacks from your opponent.
  
• Mark of Attack Damage: Because otherwise you'll lack of damage in early. And farming without those ones make it reaaaaaaally harder.
  
• Glyph of Magic Resist: You'll often face AP champions on Top, also usefull when you'll gank Midlane.
  
• Quintessence of Movement Speed: This is important in our build, remember that we need to own the top half of the map.

I'll add some tips when I will discover some. rift scuttler

Healing on Rift Scuttler

Alright, this is probably the famoust tip I can give, he concerns the Rift Scuttler. This one can be used in 2 different situations. - Safe first 5 minutes : when you arrive in lane, take level 2 on first wave, if the lane is pushed enough you can move, otherwise wait for second wave. Go kill him with your bump, than will grant you visibility to counter the gank from the jungler in the opposite team. - Simple heal : go kill him any time, he doesn't hit and can allow you to use your W. This can allow you to stay longer in lane when needing few more gold.