Free to play cards are often trash, but LR Vegito is just OP!
However, it would be time consuming to rainbow this card and Dr. Muffin, being the paragon of efficiency, hates wastes of time.
1. Get your first Vegito card (i.e., Determined Fusion Vegito) from Baba shop.
To purchase him you’ll need Supreme Kai Stones, so be sure to accomplish some Supreme Kai’s trials first.
2a. Get the other four Vegito cards from Baba shop to open hidden paths. Get sure to open all the paths before dokkan awaken him.
2b. Farm the Vegito card (i.e., Overflowing Power Vegito) from the Vegito event (stage 1, Z-hard level of Supreme Fusion! Blazing Potara). Overflowing Power Vegito has 50% to raise the special attack of your Vegito.
But remember, it is a chance, not the level of completion of the special attack bar. Which means that you could use 5 Overflowing Power Vegito to feed your Vegito and get nothing (or 5 SA levels if you are lucky). You’ll need 18 Vegito drops to max his SA. Overflowing Power Vegito drop rate is around 1/3 and the stamina cost of each trial is 10. On average you will need to repeat the level something like 54 times (total stamina cost: 540).
3. Collect the necessary (30) Awakening Medals: Potara from Supreme Kai’s trials to get Engraved Strength Vegito.
4. Collect further 70 potara medals to get All or Nothing Super Saiyan God SS Vegito (LR).
5. After Dokkaning Vegito to LR, you can use Elder Kais to raise his SA to max (i.e., 20).
Enjoy your LR and remember to share the Healing Muffin Ki with your super sayan friends!