How did you spec/build your Heimer support the other day?
So yeah, Heimer is another support that I'm looking at specifically to tackle Thresh and Leona. I wish I could stick with Ziggs and Fiddle for bot lane but until the Lulus and Jannas make a return it's impossible. You can be a hellish nightmare of harass and denial, eat one hook, and lose the entire lane. The risk vs return playing harass oriented supports is out of line right now. Leona has literally the highest health regen in the game and when you throw a Doran's Shield and S4 defensive masteries on top there's just no way of actually crippling her anymore. She's going to walk back and forth for 30 seconds and be right back on you.
With Heimer you've got his +10 health regen passive (Heimer's base regen is 0 + .6 per level) for allies and turrets so that's pretty decent bonus sustain for your ADC. Rockets are a trap. Empowered Rockets are a trap. At the start of the game if you get somewhere fast you can set up 3 turrets before a buff spawns. You can get cute with all kinds of prep locations or just give your jungler the literal best leash in the game. Turrets only cost 20 mana at all five ranks now and even with their frailty are Heimer's best button. If you are paying attention you can use them on reaction to block Thresh/Blitz hooks or other skillshots. The range on Hextec Grenade isn't great but it's an AE stun if you land it square or an AE slow if you don't. The cooldown, mana cost, and damage are all acceptable.
What I've been doing right now is going 0/21/9 with all four ranks of Legendary Guardian (the bonus Armor/MR for nearby enemies mastery), starting Doran's Shield, and showing up to lane with the sole objective being to punish an engage. I use turrets defensively, placing them far enough behind us in lane that they aren't vulnerable but close enough to be somewhere I can retreat to. Three turrets prepped with their little nuke is a ton of damage. I'll do a little harass with some autos, maybe use a grenade to deny, but all I'm really trying to do is wait for the enemy to get impatient. The ultimate I use 95% of the time is the empowered turret. If we get ganked bottom I slap that down, throw a stun, and cheese it. When I first got going with Heimer I kept seeing his empowered Grenade is a Sona ult and it's just not. It's really, really shitty. As more CC it's alright and as counter engage it's OK but as initiation it's shit. It has way more in common with Nami's ult than Sona's.
For items I start Doran's like I said and then start working on Talisman of Ascension, Sightstone, Banner of Command, and then Sorcs and Haunting Guise if the game is still going. Nothing fancy. Banner of Command is absolutely nuts on Heimer and combined with Talisman is 40% CDR with zero contribution from runes or masteries.
As much as I like Heimer he's a situational counterpick
at best.His harass is shit. His rockets are a trap. His turrets are frail. His counter-engage is excellent. His objective control is excellent. It feels pretty awesome to show up at a tower, slap down three turrets, an ultimate turret, and push it right down. His peel is average. I think he's got a place right now given the current situation in bot lane but if it goes back away from tanks to mages I'll shelve him instantly.