(I'm guessing that dndtools doesn't have some of the language/text.)
Class Features: At each level after 1st, you gain class features (including spellcasting ability) and an increase in effective level as if you had also gained a level in a class to which you belonged before adding the prestige class level. You do not, however, gain the benefit of your previous class’s Hit Dice, attack progression, skill points, or saving throws. If you had more than one class before becoming an uncanny trickster, you must decide to which class to add each level for the purpose of determining class features.
Bonus Trick (Ex): At each level, you gain a bonus skill trick for which you meet the prerequisite. These bonus tricks do not cost skill points and do not count against your maximum number of skill tricks available.
Adaptation
The uncanny trickster is already a very generalized prestige class that can easily fit into any campaign setting. It does rely on the new rules for skill tricks, however, so it is not suitable for a campaign that does not incorporate them. Replacing bonus tricks with extra feats that enhance movement and defense can repurpose the character as a sneaky combatant with a more generalized approach to skills.
Class Features: At each level except 1st and 7th, you gain class features and an increase in effective level as if you had also gained a level in a class to which you belonged before adding the prestige class level. The specific class features you gain include spells per day (and spells known, if applicable), improved chance of turning or destroying undead, metamagic or item creation feats, bonus feats, monk special abilities, sneak attack progressions, and so on, depending on the class. You do not, however, gain the benefit of your previous class’s Hit Dice, attack progression, skill points, or saving throws. If you had more than one class before becoming a legacy champion, you must decide to which class to add each level for the purpose of determining class abilities.
So it should go like this:
Level 10Uncanny Trickster 1: extra feat, favourite trick
Level 11Legacy Champion 1: Reduced ritual cost (lesser), bond of lore
Level 12Legacy Champion 2: Replace legacy ability (least) +1 level of Uncanny Trickster class features
— Uncanny Trickster 2: extra feat, favourite trick, +1 level of Legacy Champion class features
— Legacy Champion 3: Extra legacy ability use (least) +1 level of Uncanny Trickster class features
— Uncanny Trickster 3: extra feat, favourite trick, tricky defense, +1 level of Legacy Champion class features
— Legacy Champion 4: Bonus legacy feat, +1 level of Uncanny Trickster class features
— Uncanny Trickster 4: extra feat, favourite trick, +1 level of Legacy Champion class features
— Legacy Champion 5: Replace legacy ability (lesser), +1 level of Uncanny Trickster class features
— Uncanny Trickster 5: extra feat, favourite trick, +1 level of Legacy Champion class features
— Legacy Champion 6: Extra legacy ability use (lesser), +1 level of Uncanny Trickster class features
— Uncanny Trickster 6: extra feat, favourite trick, +1 level of Legacy Champion class features
— Legacy Champion 7: Reduced ritual cost (greater)
Level 13Legacy Champion 8: Bonus legacy feat, +1 level of Uncanny Trickster class features
— Uncanny Trickster 7: extra feat, favourite trick, +1 level of Legacy Champion class features
— Legacy Champion 9: Extra legacy ability use (greater), +1 level of Uncanny Trickster class features
— Uncanny Trickster 8: extra feat, favourite trick, +1 level of Legacy Champion class features
— Legacy Champion 10: Replace legacy ability (greater), +1 level of Uncanny Trickster class features
— Uncanny Trickster 9: extra feat, favourite trick, +1 level of Legacy Champion class features
— Legacy Champion 11 to infinity: +1 level of Uncanny Trickster class features
— Uncanny Trickster 10 to infinity: extra feat, favourite trick, +1 level of Legacy Champion class features
The result: the character now knows every feat related to movement and defence, and all her skill tricks can be used at least twice per encounter.