Master the Leo Warrior's Skill!
Let's look into Sira. It has a base of 20 ATK points and Defense Points of only 3. With 110 Hit Points, defense is key for her success. Where this card shines is on its Skill: Sun Reveal. You can reveal the Trigger cards under 1 target before you attack that target. By being able to see those Trigger cards before attacking give you the upper hand on seeing your opponent's board before doing damage.
Solar Slash can one-shot any card in the format currently. By losing 6 Fire Element cards for the Signature Move, it can eliminate 4 cards from your opponent's Alignment. Talk about power!
Beast Leo is the ideal partner for Flavaris. Its Skill Leo Spike increases by 5 more damage for each card discarded in the Alignment. Have 4 of these in play and combine that with Flavaris's Skill, you can have 5 attackers with 50 Attack Points in 1 go!
The main concern is the Weak Points for Flavaris. Water, Earth, and Ice can increase damage for the Leo Warrior. Search for Trigger cards like Aqua Retreat to help reduce the chance of being Perished.
Those are some pro tips for this deck. Try out your own combinations and see what potential you can unlock with Leo Burst!