Unfortunately using Chappa means you have to carry a truck of SP potions are use them as soon as they’re out CD for damage burst, and they even have been nerfed (+damage instead of +matk).
Rexipher is just + critical attack, card is fodder now.
Helgasercle is pointless (+50 matk) since you have Mothstem that gives more fixed attack (+70 matk while using strike weapon, which includes staves and rods). For my wizards where I don’t have Chappa, I use Mothstem which is easier to get. The only problem is that these cards have not been updated and since re:build are now giving a negligible attack boost (+210 matk for 3 level 10 Mothstem cards, which is less than a mere level 6 blue gem socketed on a weapon or shield).
Most efficient way to level up cards: card album event. If you’re in a guild, they organize them quite frequently. Otherwise, gather some card albums and shout for “monster album event” – with 5 parties of 5 people all bringing 5 albums, you’ll end up with 125 cards/card enhancements for everyone, which is enough to level up two of your cards to level 10 and have spares.