Splendid Tanks the Moon
In his fight against Splendont, Splendid tanks Splendont hitting him with the moon while moving it fast enough to set it on fire.
Seeing as this was done coming from space, we'll use the speed to catch on fire (1715 m/s) as a low end and 11200 m/s (Reentry speed) as a high-end
Mass of the moon is 7.34767309e+22 kg
KE = 1/2 M x v^2
= 1/2(7.34767309e+22) x 1715^2
= 3.6738365e+22 x 2941225
= 1.080558e+29 Joules, 25 Exatons of TNT, Multi-Continent level+
KE = 1/2 M x v^2
= 1/2(7.34767309e+22) x 11200^2
= 3.6738365e+22 x 125440000
= 4.6084605e+30 Joules, 1 Zettaton of TNT, Small Planet level
DMUA Edit:
Splendont pushed the Moon from orbit to Earth in 15 seconds
Distance to the Moon is 384400000 m
384400000 / 15 = 25626666.6667 m/s
= 1/2(7.34767309e+22) x 25626666.6667^2
= 3.6738365e+22 x 6.5672604e+14
= 2.4127041e+37 Joules, 5.7 Ronnatons of TNT, Large Planet level
As Splendont accelerated the moon basically instantly...
F = MA
= 7.34767309e+22 x 256266.666667^2
= 4825408284279141535714657052970100 Newtons, 4.920371453328e+32 Kilograms of Force, Stellar Lifting Strength
Splendid Flies to Space

In the episode Better off Bread, Splendid flies from the Earth's surface to far away from the planet in two seconds.
Diameter of Earth is 12742 km, or 12742000 m
2atan(tan(70/2)*(416/700)) = 0.548948915 rad = 31.4524559978637903 Degrees
Plugging into the Angsize Calculator yields 2.2626e+7 m
Seeing as Happy Tree Friends characters are around human sized (Can drive human sized vehicles, live in human-sized houses, etc.) we'll use 1.7m as Splendid's height
2atan(tan(70/2)*(353/700)) = 0.469081147 rad = 26.8763699723224256 Degrees
Plugging into the Angsize Calculator yields 3.5574 m
2.2626e+7 - 3.5574 = 22625996.4426 m
22625996.4426 / 2 = 11312998.2213 m/s, .037c, Sub-Relativistic
Splendid Reverses the Earth's Rotation
In the episode Better off Bread, Splendid stops and then reverses the rotation of the Earth, circling the planet at extremely high speeds.
Rotational KE of the Earth is 2.138e+29 Joules
It takes him 2 seconds to stop the Earth, so divide that by 2 = 1.069e+29 Joules, 25 Exatons of TNT, Multi-Continent level+
Borrowing this calc method
Splendid Circles the Planet: 2:19:53
Splendid Circles the Planet Again 2:19:54
Diameter of Earth= 12742 km
12742 / 416 = 30.6 km/px
Diameter of Flight Ring = 659 px
659 x 30.6 = 20165.4 km
2:19:54 - 2:19:53 = 0.01 s
C = pi*d = pi*20165.4 = 63351.47 km = 63351470 m
63351470 / 0.01 = 6335147000 m/s, 21c, FTL+
Splendid's Heat Vision Causes an Explosion

In the episode From Hero to Eternity, Splendid causes a massive explosion with his heat vision.
Diameter of Earth is 12742 km
12742 / 1093 = 11.6 km/px
11.6 x 112 = 1305.67 km
Y = ((x/0.28)^3)
= ((1305.67/0.28)^3)
= 101397251412 kilotons
= 101.4 Teratons, 4.242576E+23 Joules
Large Country level
Splendid Flies to Space Again
In the episode Gems the Breaks Splendid flies from a few meters above the Earth's surface to the Moon in 4 seconds
Distance to the moon is 384400000 m
384400000 / 4 = 96100000 m/s
0.32c, Relativistic
Final Tally
Splendid Heat Vision: 4.242576E+23 Joules, 101.4 Teratons of TNT, Large Country level
Splendid Tanks the Moon: 2.4127041e+37 Joules, 5.7 Ronnatons of TNT, Large Planet level
Splendid Stops the Earth from Spinning: 2.138e+29 Joules, 25 Exatons of TNT, Multi-Continent level+
Splendid Speed: .037c, Sub-Relativistic
Splendid Speed 2: 0.32c, Relativistic
Splendid Speed 3: 21c, FTL+
Splendid Lifting Strength: 4.920371453328e+32 kg, Stellar