@Catpone Cerberus
Sombra would snarl at Flint, of which Flint may consider it amusing it was basically Rarity snarling at her. Sombra would quickly dodge the knife that was thrown his direction - he had combat experience in war, so he knew how to hold a fight. Though Flint would very likely prove she was no traditional opponent - as her seemingly just standing there taking the blows Sombra did towards her. Sombra also took note that her whole body was seemingly glowing with magic - so it was clear to him she did not have traditional magic.
The blades had seemingly failed to do any real damage to her - so this called for a more direct approach. Sombra then began charging right at Flint's direction, though would randomly skip and jump side to side in an unpredictable manner that seemed to be rather unusual for someone to be able to do. His horn was glowing with dark magic, so it was likely some kind of dark magic spell that he was doing on himself. As he charged towards Flint, suddenly he would begin shooting black crystals towards her direction - though they would not actually hit her, but land in various spots in a circular pattern around her and begin rooting themselves into the ground quite rapidly - while also rapidly expanding as well. He wanted to try to ensnare her in a trap or try to damage her with the crystals. As this process happened, he kept shooting them towards the ground, making the process exponential.
Sombra was furious - and had the intent on doing severe damage to Flint. Only way he would stop is if Flint somehow forced him to stop, or if there were other ponies who stumbled into the area, if there were - he would grab Una in his magic and rapidly withdraw from the scene - using his magic to dispel all of the black crystals and dark magic from the area. If there were no such interruptions, he would aim to gain a tactical advantage. Right now he wasn't focusing that much on Una, but was concerned about the possibility of Flint doing some kind of mind altering spell on Una to make her not listen to him, or something of the sort.