Hello everyone and welcome to my 123rd analysis, this time featuring Warthak the Mountainsplitter.
Mountainsplitter destroys any Earth monster with his Base 80 Dark move(except Ouros), and has a pretty good Speed for an Earth monster-the fastest of the 3 Warthaks. Warthak's moves may not have impressive effects like the other Nemeses, but his trait more than makes up for it by making him a good answer to almost any denier. Like other Nemesis monsters, Warthak has simply amazing stats all around. However, Warthak is still prone to Mega Stun, Stamina Drain, CDs Activated(maybe) and Stop Time, which, even while being found on few monsters, are threats. Blind and Daze are also annoyances to a lesser extent.
(If you have all Group 3 moves learned on a Nemesis monster at the same time, the next time you'd normally learn a Group 3 move, a Group 4 move will show up instead. Using this method it's possible to have 2 Group 4 moves on a level 100 Nemesis, by replacing the 4th move you have with the Group 4 you're offered, then replacing one of the Group 3 moves with the other Group 4.)
-Dawson Ghost
-Mountainsplitter Stroke
-Restored Petroglyph
-Single-Handed Mountainsplitter
Runes: 2 Strength 1 Speed

This moveset represents Warthak without his Group 4 moves, and admittedly, is not as bad as, say, Lucifire's version. Dawson Ghost deals hefty damage to its target, removes all positive effects on it-which is nice considering its ability to remove Shields, Double Life and Return Damage- and applies Damage Reduction. Mountainsplitter Stroke has 0 CD, is a Dark move and has 60 Base Power-in addition, it applies Bleeding and Daze to target which heavily reduces damage. Restored Petroglyph has an awesome 40 Base Power, blocks and removes all Shields from the enemy team for 3 turns, and interestingly has 100 accuracy, which is a godsend for an AOE. Lastly, Single-Handed Mountainsplitter will knock out most monsters without Life runes in one-hit and if they survive, Stuns and applies Bleeding to them. 2 Strength 1 Speed maximizes damage.

(For this next moveset, I'll consider the move Marikana Wraith as an AOE because it's ridiculously obvious that it is)
-Two-Handed Mountainsplitter
-Perfect Petroglyph
-Marikana Wraith
-Mountainsplitter Stroke
Runes: 2 Strength 1 Speed

This is the moveset Warthak has at Rank 3. Pick up the Group 4 moves in this order: Marikana Wraith, Two-Handed Mountainsplitter, Perfect Petroglyph. Two-Handed Mountainsplitter is an upgrade to Single-Handed Mountainsplitter that is even more guaranteed to kill with the same side effects. Perfect Petroglyph is the perfect AOE move: it has the golden 45 Base Power and 100 accuracy. Marikana Wraith has a great 40 Base Power, is unresisted, and removes all positive effects from the enemy team in addition to applying Damage Reduction, which greatly improves his already good matchup vs. Fire monsters. Lastly, Mountainsplitter Stroke is chosen instead of Single-Handed Mountainsplitter because one of the few ways Warthak can get denied is CDs Activated, and this move makes it so that doesn't happen. 2 Speed 1 Strength for the same reasons.

Teammates: Warthak is the definition of a one-man army, but who doesn't want teammates? Demise can allow his Dark attacks to kill anything with Strength From Beyond. The biggest threat to Warthak is Stamina Drain, which is found on many Water monsters, so Frostbite in a Water War will greatly help with Arctic Boost. General Ingvar can remove all negative effects on him and also gives him Stamina Regen, which solves all of his weird deny effect problems.

Countering Warthak the Mountainsplitter: Among Earth monsters, Hiroim the Tenacious and Brontes stand as the best counters since Warthak isn't immune to Mega Stun, though the AI may not be as smart as you are if Warthak is on the attacking player's team. Pigredo can activate his CDs, but his Mountainsplitter Stroke will still do tons of damage. Among other elements, use monsters that can use the status effects I listed in the beginning of my analysis(Stop Time, Mega Stun,etc.).