Example output
Let's start by discussing your champion selections.
Yasuo is a high-damage champion that can be a great pick for aggressive players. However, he can also be a high-risk champion due to his low health and lack of mobility. To improve your gameplay with Yasuo, I recommend focusing on your positioning and timing. You should be constantly moving around the map, looking for opportunities to engage the enemy team and deal damage. Try to stay behind your tankier teammates, so you don't get caught out of position and targeted by the enemy team.
As for Sejuani, she is a tanky champion with great crowd control abilities, which makes her a strong pick for team fights. As an aggressive player, you can use Sejuani's crowd control abilities to engage the enemy team and create opportunities for your teammates to deal damage. However, you should also be careful not to overextend and put yourself in a dangerous position. Focus on using your abilities to peel for your teammates, protect them from the enemy team's attacks, and set up kills for your team.
In terms of build recommendations, for Yasuo, I suggest building a combination of attack damage and critical strike items, such as Infinity Edge, Phantom Dancer, and Bloodthirster. For Sejuani, building tanky items like Sunfire Cape, Spirit Visage, and Dead Man's Plate can help you stay alive in team fights and absorb damage for your team.
Remember to communicate with your team, coordinate your engages, and focus on objectives. These tips should help you improve your gameplay and rank up based on your aggressive playstyle. Good luck on the rift!