Vader's force feats showings such as telepathically commanding Cyclo's massive Living ship to fly into a star, collapsing towers, using barrier to withstand the explosion of Cymoon 1 (One of the largest Imperial bases), exploding Lyleks (A Lylek is a massive insect with a hide thicker than armor/that can besiege cities), destroying an AT-AT, shredding Vulture droids with a wave of his hand, manipulating freighters, blowing a massive hole into ETA shuttles by just being angry, etc (these are all only his canon showings)
As for saber feats in canon he's beaten Ahsoka who has fought evenly with Maul, who in turn was stomped by Ben Kenobi. If we're using composite versions he's beaten Ben Kenobi, Galen Marek, Starkiller, fought off multiple Jedi off at once while being in his suit for only a month, and was considered the greatest living swordsmen in the OT era.
Beating Ben who stomped Maul is frankly better than anything Arcann has done.