Heliolisk to B
With the subtraction of Serperior from UU, Heliolisk suddenly has become one of the tiers best counters to bulky-waters, which have become much better in this meta due to a lack of Serperiors. As an extra way to counter these waters, it has dry skin so it can switch into a scald or surf, and a Thunderbolt can do a lot of damage.
Against Crocune-252 SpA Life Orb Heliolisk Thunderbolt vs. 252 HP / 0 SpD Suicune: 304-359 (75.2 - 88.8%) -- guaranteed 2HKO after Leftovers recovery
Against Vaporeon-252 SpA Life Orb Heliolisk Thunderbolt vs. 200 HP / 56+ SpD Vaporeon: 304-359 (67.4 - 79.6%) -- guaranteed 2HKO after Leftovers recovery
Against Tentacruel-252 SpA Life Orb Heliolisk Thunderbolt vs. 240 HP / 0 SpD Tentacruel: 289-343 (80 - 95%) -- guaranteed 2HKO after Black Sludge recovery
Against Empoleon-252 SpA Life Orb Heliolisk Thunderbolt vs. 252 HP / 252+ SpD Empoleon: 242-289 (65 - 77.6%) -- guaranteed 2HKO after Leftovers recovery
Against Blastoise-252 SpA Life Orb Heliolisk Thunderbolt vs. 236 HP / 0 SpD Mega Blastoise: 304-359 (84.9 - 100.2%) -- 6.3% chance to OHKO
At the same time, it is able to hit the tier's ground for a lot of damage with a grass knot or HP Ice.
Against Krookodile-252 SpA Life Orb Heliolisk Grass Knot (80 BP) vs. 0 HP / 4 SpD Krookodile: 268-317 (80.9 - 95.7%) -- 12.5% chance to OHKO after Stealth Rock
Against Gligar-252 SpA Life Orb Heliolisk Hidden Power Ice vs. 252 HP / 4 SpD Eviolite Gligar: 286-338 (85.6 - 101.1%) -- 81.3% chance to OHKO after Stealth Rock
Against Donphan-252 SpA Life Orb Heliolisk Grass Knot (100 BP) vs. 172 HP / 0 SpD Donphan: 380-447 (104.3 - 122.8%) -- guaranteed OHKO
Against Swampert-252 SpA Life Orb Heliolisk Grass Knot (80 BP) vs. 240 HP / 0 SpD Swampert: 442-520 (110.2 - 129.6%) -- guaranteed OHKO
Against Mega Swampert-252 SpA Life Orb Heliolisk Grass Knot (100 BP) vs. 104 HP / 0 SpD Mega Swampert: 468-551 (127.5 - 150.1%) -- guaranteed OHKO.
Against Flying Types, Grass Types, and Dragons, HP Ice does a lot of damage.
Against BulkyMence-252 SpA Life Orb Heliolisk Hidden Power Ice vs. 252 HP / 0 SpD Salamence: 364-432 (92.3 - 109.6%) -- guaranteed OHKO after Stealth Rock
Against Mega Aero-252 SpA Life Orb Heliolisk Thunderbolt vs. 0 HP / 0 SpD Mega Aerodactyl: 354-421 (117.6 - 139.8%) -- guaranteed OHKO
Against Crobat-252 SpA Life Orb Heliolisk Thunderbolt vs. 248 HP / 4 SpD Crobat: 406-478 (108.8 - 128.1%) -- guaranteed OHKO
Against Mega Scep-252 SpA Life Orb Heliolisk Hidden Power Ice vs. 0 HP / 4 SpD Mega Sceptile: 348-411 (123.8 - 146.2%) -- guaranteed OHKO
Against Shay-252 SpA Life Orb Heliolisk Hidden Power Ice vs. 0 HP / 4 SpD Shaymin: 151-179 (44.2 - 52.4%) -- 79.3% chance to 2HKO after Stealth Rock and Leftovers recovery.
Even against all of these commonly used Mons, Heliolisk shines through as a powerful mon, and having 109 SpA and 109 Spe allows it to outspeed many of these threats, so Heliolisk to
B.